Ten days after Nevado del Ruiz volcano erupted, pushing a river of mud down its slopes and burying the town of Armero, survivors and Colombian authorities are bitterly disputing who is responsible for the almost 23,000 deaths and the devastation.

The fact that there had been warning of the tragedy has made it even more disturbing for many Colombians. A team of scientists studying the mountain, which started rumbling last December after 140 years of inactivity, advised the government five weeks before the Nov. 13 explosion that any significant eruption would produce floods and mud slides in valleys below. Their estimates turned out to be hauntingly accurate, with an official toll now of 22,940 dead, 4,235 injured and 4,555 homes destroyed.

Survivors of Armero, where 20,808 perished, according to the government, blame Colombian authorities for not evacuating the town in time. Senior government officials, in turn, say townspeople ignored notices of imminent danger distributed by Civil Defense and Red Cross officials weeks before.

Whatever the truth, it was evident to many who watched that once the disaster happened, the rescue effort was fumbled. Relief workers lacked the equipment and training to save people buried up to their necks in mud and debris. International rescue teams arrived late and then were trapped in red tape that delayed their arrival at the disaster site.

Government ministers at one point seemed to be at odds over how long to continue searching for the living. They also panicked communities around the volcano's base by sounding a false alarm about an alleged eruption three days after the original one.

Government officials maintain that they did the best they could under circumstances that any country would have found overwhelming. They pointed out that Colombia is a developing country without the sophisticated methods and sense of organization known in the United States or Western Europe.

It is also a country drained by other ongoing crises, particularly an intensified war between government forces and leftist guerrillas. When the eruption of Nevado del Ruiz occurred, Colombians were still mourning a bloodbath at Bogota's Palace of Justice, seat of the Supreme Court. About 100 died there, including 11 of 24 Supreme Court justices, during a takeover of the building Nov. 6 by M19 rebels. The assault was crushed by Army and police troops.

As the nation's grief shifted last week to the 23,000 killed by the volcano, the guerrilla war continued. A combined group of M19 and Popular Liberation Army rebels seized the town of Urrao in western Colombia, fleeing after a seven-hour gun battle with police. A few days later, a leader of the Popular Liberation Army, Oscar William Calvo, was gunned down in Bogota.

M19 issued a communique at the week's end saying it had suspended attacks in urban areas in deference to the Armero disaster, but few here expected the violence to cease for long.

The renewed attacks have shattered the semblance of peace that President Belisario Betancur had achieved by negotiating fragile cease-fires with four rebel groups. With disaster piling on disaster, the bishops of Colombia's Roman Catholic Church published a communique yesterday pleading for national unity. They urged "no more violence that takes lives and collapses order and law."

Towering above Colombia's Central Range, the 17,700-foot-high Nevado del Ruiz until recently had seemed one of the last places a new national drama would start.

A volcanic earthquake in 1845 released an avalanche that killed 1,000 people below. But the rich load of dumped earth eventually provided fertile soil for cotton, rice, coffee and other crops, and the region prospered. Nothing more was heard from the volcano, its serene snow-capped peak becoming an attraction for hikers and skiers.

Suddenly last Dec. 22, the volcano started gurgling and smoking. Within several months, an informal study team of scientists privately concluded that the chance of a lava flow was slight but an explosion of ash and stone was probable.

In casual contacts with politicians, diplomats and others, they started spreading word that if such an explosion occurred, it would trigger an avalanche of melted ice and mud that would pour into river beds around the volcano, submerging towns and farms.

By September, the Colombian press had picked up the story. Photographs of the plume of smoke that floated above the cone of Nevado del Ruiz accompanied front-page articles about the volcano.

Then interest waned. Nothing had happened and, some people figured, nothing would.

Consulting with international specialists, including Darrell Herd of the U.S. Geological Survey, whose doctoral thesis in the early 1970s focused on Nevado del Ruiz, Colombian experts prepared a "volcanic risk map" outlining the probability of various types of eruptions and their consequences.

A preliminary report, issued Oct. 7, stopped short of predicting an imminent eruption but called for a stepped-up observation effort using more sophisticated sensing equipment. The risk map drawn then clearly showed that if the volcano exploded, the town of Armero would be buried in a mud flow.

Victor Ricardo, general secretary of the presidency, said in an interview yesterday that in view of the scientists' finding, Civil Defense and Red Cross teams conducted a house-to-house education campaign in Armero and other towns surrounding Nevado del Ruiz to warn of the volcano's danger.

But when the eruption happened, the official order to evacuate was slow in coming from the office of the governor of Tolima province, and the people of Armero reportedly had little idea of where to run.

Ricardo said residents of the town had been reluctant to heed earlier warnings.

"People who are used to living for more than 100 years at the base of a volcano . . . become very attached to their possessions," he said. "They believe they can get through a crisis without abandoning their town. They don't realize the enormity of the disaster that can occur."

Armero survivors have reported that instead of calling an evacuation, the mayor, the priest and the local radio announcer all insisted there was no cause for alarm when, after 3 on the afternoon of Nov. 13, an eruption of Nevado del Ruiz produced a rain of ash.

A second volcanic blast occurred at 9 p.m., shooting a hot column of ash and glowing stones into the air. Landing on the volcano's ice cap, the burning cinders melted about 5 percent of the ice, sending mud and debris rushing down the mountain.

Less than two hours elapsed before the raging mud flow engulfed Armero. The town did not awake to the threat until sometime after 10 p.m. At about that time, the governor of Tolima, Eduardo Alzate, broadcast an evacuation order. By then, though, it was too late.

Adding to the charge of governmental irresponsibility in preparing for the disaster has been the story of a natural dam above Armero. Geologists had advised regional authorities to drain the dam, lest it break and flood Armero. But nothing was done.

It broke under the force of the mud avalanche from Nevado del Ruiz. The National Emergency Committee last week issued a communique insisting that the water released from the reservoir had made little difference in the destruction of Armero.

Still, some Armero residents said the lack of action on the dam by state authorities was symptomatic of the government's alleged inattentiveness to the threat.

"When we needed the money to drain the dam , no one gave it," said Alexander Torres, 23, whose father, Rosendo Torres, was twice mayor of Armero and perished in the disaster. "Now, everyone is giving money."

Moreover, though rescue organizations had warned of the danger of mud flows, they were ill-prepared, as was the government, to deal with disaster when it struck.

They lacked sophisticated thermal imaging and sonar equipment to search for people buried in the mud, which is understandable given Colombia's underdevelopment. But also absent were simpler rescue tools, such as water pumps, cutting instruments and wooden planks to help people move across the mud.

"We have had a tremendous lack of equipment due to limits on imports," said Guillermo Rueda, who heads the Colombian Red Cross.

Because roads to Armero were cut by the flood, the rescue effort was essentially an air operation. Military helicopters were called in, and the military assumed command of the relief campaign, directing where field hospitals would go -- they were put in several towns away from Armero -- and ferrying emergency supplies of drugs, clothing and food to relief centers.

But few soldiers were sent to Armero to look for buried survivors. Asked why, Defense Minister Gen. Miguel Vega Uribe said in an interview yesterday: "My job was not to put people in there but to get them out. I didn't want my own people to sink."

Red Cross and Civil Defense workers, along with volunteers from neighboring towns, conducted most of the mud searches. But there never seemed to be more than 50 or so official rescuers combing the 12-square-mile disaster area at any one time.

Although government officials strongly deny it, the reason for the limited search crews, according to others involved in the rescue effort, was an early judgment that hardly anyone was left alive in Armero's mud-covered ruins.