Rescue operations for survivors of last week's giant mud flow resumed today under public pressure to continue searching and, almost miraculously, several persons who were buried for five days in this submerged, rotting town were found alive.

Army commanders involved in salvage actions said they had received fresh orders this morning extending the rescue effort for another two days, although they doubted that more than a few additional victims would be located and lifted still breathing from the mud covering this devastated agricultural community.

"Some people say they still hear cries, but it's very unlikely there are survivors" in Armero, said Army Capt. Jose Domingo Garcia, interviewed at a military staging operation at Mariquita Airport about 20 miles north of here. The captain said orders arrived at 6 a.m. today stretching rescue activities another 50 hours.

As the country struggled to come to grips with the dimensions of the deadly mud slides triggered by eruptions of the Nevado del Riz volcano, it received an abrupt reminder today of the guerrilla war that brought international attention to its capital only 11 days ago.

One hundred fifty leftist guerrillas were reported to have seized the town of Urraro, located about 180 miles northwest of Bogota. Colombian radio said that the rebels, a combined force of the Movement 19 and the Popular Liberation Army, had taken more than 100 persons hostage. A priest hiding in a church in the town phoned Radio Caracol this afternoon saying the guerrillas were in a gun battle with 35 police.

After M19 rebels seized the Palace of Justice in Bogota Nov. 7, the Colombian Army laid a 27-hour siege to the building. More than 85 persons were killed, including rebels, soldiers, police, court officials and employes, visitors and 12 of Colombia's 24 Supreme Court justices.

But national attention and mourning remained focused on Armero, which lay in eerie silence today under a great brown expanse of mud, yards thick, caking on the surface in the Colombian heat.

Concern that decomposing bodies -- estimated at more than 22,000 -- were posing a serious threat of typhoid, tetanus and other epidemics led to the evacuation of rescue workers yesterday and a declaration from the minister of health that the disaster site would be closed to traffic and treated with chemicals.

That decision, however, was reversed or overruled late yesterday by other government officials after relatives of Armero victims objected to halting the search for the missing.

"The government initially thought there was nothing more to do there," said Arturo Fuentes, an Army major operating out of Mariquita Airport. "But given the evident facts, an extension of two days was given."

After four days of what had appeared to be uncoordinated attempts to search the gooey, decaying morass of collapsed buildings and twisted debris that once was Armero, rescue workers today followed a more organized plan.

A "zone of silence" was declared over the town this morning, during which helicopter flights were halted. A team of about 30 or 40 Civil Defense members and several policemen stationed themselves in various quadrants of the town and listened for sounds from any survivors still buried, according to Jorge Uribe, a Jesuit priest from the University of Javeriana in Bogota who witnessed the operation.

They heard a noise.

It led them to a teen-age girl, who was pulled alive from a house that had been blocked in the front by debris and in the back by another fallen house.

A group of volunteer firemen from the neighboring town of Honda who were scouring the northern edge of Armero reportedly discovered an 18-month-old baby lying still conscious in the mud, as well as a young girl, who was described by other rescue workers as extremely dehydrated and nearly unconscious.

To guard against the spread of disease, workers in some parts of Armero were pouring a strong disinfectant on corpses. Civil Defense officials here said that after search operations cease, there is a plan to cover the disaster zone with lime to hasten the decomposition of bodies.

Aid from around the world continues to pour in. According to Colombian radio, for instance, Danielle Mitterrand, the wife of the French president, arrived today with several tons of French emergency assistance, as well as a team of specially trained search dogs, according to Colombian radio.

Transportation of foreign assistance here has also led to some international frictions. In one publicized incident, the Nicaraguan government prohibited British helicopters en route to Colombia from refueling in Nicaragua or crossing Nicaraguan airspace. Colombia has officially protested the refusal.

Just what is to happen to Armero once the salvage operation is finished remains unclear. Engineers at the Ministry of Public Works have been quoted in the Colombian press as saying that the reconstruction of the city is virtually impossible given the extent of the destruction and the tons of mud dumped on it.

Reports persist that the town may be declared a graveyard, but the Roman Catholic Church so far has not taken the necessary religious steps to effect this.

President Belisario Betancur met today with political party leaders to discuss an economic emergency plan for the area around Nevado del Ruiz, the volcano whose explosion last Wednesday caused the flooding of Armero and parts of other towns.

Aside from the physical recovery of the region, there is the painful process of sorting out the thousands of families ruptured by the tragedy. The dilemma of hundreds of children orphaned by the flood has become a focus of Colombian press attention.