Efforts to save hundreds of people trapped in the wreckage of Wednesday's flash floods were stepped up today, but Red Cross officials in the disaster zone in central Colombia said victims not lifted to safety by tonight stood little chance of survival.

The number of survivors being dug out of Armero's rubble had dwindled to a few by this morning. Only two had been found between dawn and 11 a.m. today. Relief workers, who yesterday estimated that 1,000 to 2,000 people might be alive in the submerged town, today said they believe that 200 at most were still alive.

In Bogota, the government said about 22,300 people had died in the floods and mud slides that followed Wednesday's eruption of the Nevado del Ruiz volcano.

Unconfirmed reports of new activity at the top of the volcano triggered a panic in several towns around the mountain. A pilot flying by the volcano claimed to have seen a dense cloud of sulfur, and radio stations broadcast reports that there might have been one or two new explosions. But other reports early this evening indicated that the situation was not threatening. In this town, where most of the destruction from Wednesday's volcanic eruption and mud slides occurred, doctors continued to complain of insufficient medical supplies, manpower and salvaging equipment, while the search for people still alive beneath the morass of collapsed buildings and twisted vegetation had little direction.

At Palanquero Air Force base 36 miles to the north, headquarters for the military relief effort, Gen. Alberto Melendez, the base commander, acknowledged that Colombian authorities were staggered by the enormity of the tragedy. He said the task of digging out Armero, a town of 25,000 almost totally destroyed when the volcano erupted Wednesday, causing hunks of glacial ice to melt and flood rivers below, was more than official agencies could manage quickly.

"There are just too many people to search for, to fight for," the general said in English to a group of foreign reporters. "I don't know if anyone in the world could figure out what to do. If he could, then he is quite close to God."

As he spoke, crates of clothing and medicine were being loaded onto two U.S. military CH47 cargo helicopters, part of a fleet of 12 American choppers flown to Colombia from Panama yesterday and today by the U.S. Army's 210th Aviation Battalion of the 193rd Infantry Brigade. The helicopters were put into service transporting the wounded and ferrying supplies to several field hospitals set up yesterday in neighboring towns in the Magdalena River valley.

The U.S Air National Guard also flew a C130 cargo plane to Colombia yesterday filled with 500 tents, each large enough to sleep six to eight people. But, according to Navy Cmdr. Frank Evans, spokesman for the 105-man U.S. contingent sent to Colombia, a decision on what further American assistance to provide was awaiting a report by a U.S. aid official who toured the devastated region this morning.

Tons of emergency material have been shifted south from Palanquero to the civil airport at Mariquita, now a military-controlled staging point for relief operations.

Melendez said the number of sorties flown by military aircraft out of Palanquero carrying emergency supplies tripled today over the number flown Thursday. But hardly any of the supplies are being forwarded to Armero. Part of the reason appears to be bureaucratic.

Additionally, authorities supervising the salvage effort have decided to limit rescue and medical operations in Armero because of the absence of electricity, potable water, telephones and other basic services.

Fernando Bendeck, national vice president of the Colombian Red Cross, said today he had dispatched only 15 volunteers to Armero.

"We can't leave more people there because there are so many difficulties with water and food," he explained at his operations base at the Mariquita airport.

He said the Red Cross had mobilized 2,000 volunteers nationwide to help in the disaster but had stationed them in hospitals and relief centers away from Armero.

Bendeck expressed his own disappointment at the sluggishness of rescue operations, saying workers lacked equipment to do the job. He had little hope of finding any more survivors in Armero after today.

"After three days, conditions are critical," he said. "Today is the crucial day."

Clusters of rescue workers continued today to pick their way across the mud-covered remains of Armero, listening for cries of help. Several helicopters hovered overhead, also hunting for signs of life.

The search had no formal organization or design. And it had major setbacks.

One came at 9:45 this morning when a 13-year-old girl, whom rescuers had spent much of the past two days trying to free from the crushed remnants of her house, died. The attempted rescue of Omayra Sanchez had been widely reported, with photographs of the round-faced, dark-haired girl appearing in newspapers around the world.

Her body lay limp this morning in a pool of brown water out of which she had struggled to climb, held back by broken concrete slabs pinning her feet. She died of a heart attack induced by exposure, according to Alejandro Jimenez, a Red Cross medic.

"We were up all night trying to save her," he said.

Someone had drapped a blue-and-white checkered cloth over the girl, a graceful symbol of mourning among ugly splintered timbers, chunks of concrete and corrugated sheets of tin.

Eduardo Talero, another Red Cross medic, said the small-scale rescue operation here was in desperate need of such basic medical supplies as antibiotics, typhoid vaccine and bandages.

"It will become necessary soon to start burning bodies, because otherwise there will be an epidemic of typhoid," he said. "Most importantly now, though, we need to have more first aid equipment."

An attitude of resignation has come over some Armero residents who said they have given up searching for lost relatives and friends.

"The place is already buried, it is already a grave," said Antonio Rubio Guzman, a construction engineer who lost 25 relatives in the catastrophe.

A mass grave has been designated in Guayabal, the closest town to the north of Armero, where about 200 bodies reportedly have been deposited. Pope John Paul II, who according to the papal nuncio to Colombia, wept when he saw pictures of the disaster here, has declared the area sacred ground so bodies can be left where they are.

In the towns around Armero, residents remained fearful of further volcanic explosions and mud slides. Rumors of imminent disaster swept through Mariquita, Honda and Lerida yesterday, triggering a stampede of people looking for higher ground.

In the streets of Mariquita today, hundreds of people milled around nervously.

Colombian geologists have said that ice flows triggered by the restless volcano may be blocking some rivers at the mountain's base, which now have shrunk to narrow streams. Government authorities have warned residents in the area to be alert for new flooding.

This evening, Communications Minister Noemi Sanin made a radio broadcast urging residents of the area around the volcano to begin an evacuation immediately. An hour later, however, she made a second broadcast saying there was no imminent danger of a new avalanche.

"The state of alert remains, but fortunately it seems that this eruption will not have the grave consequences of the one three days ago," she said.

In the early evening the government said it was sending a team of international experts closer to the mountain to survey what had happened. One expert raised the possibility that there had simply been an intense electrical storm around the volcano's summit, rather than a new eruption.

The emergency field hospital in Mariquita was sent by Mexico along with 45 soldiers to run it. Their commander, Gen. Jose Luis Gutierrez Cedeno, rescued people from the rubble of Mexico City following September's earthquake there.

The general said conditions here are much worse.

"In Mexico, there were still buildings" standing after the earthquake "with facilities and supplies," he remarked. "Here, we are in the countryside. Everything is more difficult.