The ambush that killed 18 Sandinista soldiers here and led to the collapse of the Nicaraguan cease-fire was staged with a Claymore mine, an American-made weapon used by the U.S.-backed Contras, foreign military specialists said Monday after examining evidence from the scene.
In separate testimony, a local farmer said he was certain that the Contras mounted the attack on a truckload of troops on Oct. 21 because members of his family had recognized two rebels fleeing the area that day.
President Daniel Ortega called the ambush "the last straw" in a series of Contra attacks that led him to end the 19-month truce last Wednesday. U.S. and Contra officials have refused to accept his account and have suggested that one Sandinista unit might have mistakenly fired on another.
But U.S. Secretary of State James A. Baker III, under questioning last month about the incident, noted that the Bush Administration ordered the Contras last spring to refrain from offensive operations in return for continued non-lethal aid. If that ban is violated, he said, "we have obligations (to Congress) to cut off our humanitarian assistance."
The farmer's testimony and two objects taken by reporters Saturday from the scene of the attack point strongly, if not conclusively, to a rebel attack. They are the first known pieces of independent evidence to emerge since the incident occurred near this hamlet in central Nicaragua, 20 miles from the town of Rio Blanco.
Claudio Fonseca, the Sandinista chief of state security in Rio Blanco, said his men recovered a metal wire apparently used to trigger a mine, along with scores of cartridges from FAL and AK-47 assault rifles, from a small hill overlooking a curve in the road where the army truck was hit. He did not show the evidence to journalists.
But two reporters who went to the scene found a couple of objects the investigators had left behind: a small piece of metal half-buried in a shallow hole in the hillside and an empty plastic spool hidden amid tall grass at the crest.
"There can be no doubt that these belong to a Claymore mine," a military specialist in Managua said.
He and two other experts said the metal was one of four legs used to prop up a Claymore, a deadly anti-personnel explosive that sprays shrapnel in one direction when triggered by a wire. The spool was used to hold the wire, they said.
The Sandinistas have never been known to use Claymores, the specialists said.
Luis Adan Fley, a Contra official in Honduras, said Monday that the United States stopped supplying Claymores to rebel forces years ago but acknowledged that some might still be in stock. If there are, he said, "they must be old." He refused to acknowledge rebel responsibility for the attack.
The ambush occurred in mid-afternoon as a Soviet-made flatbed truck was taking 32 army reservists from their base in nearby San Andres to register in their faraway hometowns for next year's national elections. Also aboard the truck were nine army regulars.
The mine exploded about 10 feet from the truck as it rounded a curve in the dirt road, as suggested by a hole left in the hillside by the road. The attackers were apparently hidden in high grass several yards back.
The day after the attack, Ortega met with the Sandinista army high command and reportedly decided to take the offensive against the Contras. In announcing the decision last week, he left open the possibility of re-establishing the cease-fire through new talks on demobilizing the rebel army.
On Monday, U.N. officials announced that Contra leaders have agreed to meet Sandinista government representatives Thursday and Friday for the first direct peace talks in more than a year.
Cardinal Miguel Obando y Bravo, Nicaragua's Roman Catholic primate, has agreed to attend the talks at the United Nations in New York as an observer. He has been a go-between for the Sandinistas and Contras in the past.
While all evidence implicates the Contras in the ambush here, some details of the official Sandinista account--that 40 to 50 Contras staged the attack and waged a prolonged gun battle with the survivors after the initial explosion--are disputed.
In interviews last week, three of the eight wounded survivors repeated the official version, but two of them said they never saw their assailants and doubted that anyone else did.
"We kept shooting for 25 minutes," said Juan Antonio Cantarero, the truck's 22-year-old mechanic. "But nobody saw them."
According to accounts by medical personnel, all the wounded were hit by shrapnel. Farmers here said Sandinista investigators did not recover bullet cartridges on the hill, as was officially reported; the journalists found none.
U.S. officials have cast doubt on the Sandinista version by saying there was speculation among farmers here that another Sandinista unit was in the area and might have attacked the truck by mistake.
Accidental clashes have occurred between Sandinista foot patrols, but such a clash is unlikely in this case. Armed Contras do not go around in trucks, and thus a truckload of uniformed men would not likely be mistaken for rebels. In any case, no such rumor was repeated by any of the dozen or so farmers interviewed here last weekend. They said three Sandinista light infantry battalions that had been patrolling the area left the day before the ambush.
The farmer who reported seeing two Contras fleeing the area said the pair ran into his sister-in-law's farmhouse after the attack and asked for water. He said they told her they were fleeing the army. She recognized them by their noms de guerre , Jamaica and Profeta, and said they were attached to the Santiago Meza Battalion, one of several Contra units active here, he said.
Contradicting the Sandinista account, the farmer said no other rebels were in the area that afternoon. He said he talks regularly to Sandinistas and Contras and that "anybody who moves around here we know about."
The rebel official in Honduras identified Jamaica and Profeta as armed Contra collaborators who live permanently in the area, giving information on Sandinista movements to any rebels passing through. "They are not under our control," he said. "They are autonomous."