Government officials today searched four Libyan cargo planes that had stopped in Brazil this week on their way to Nicaragua and confirmed that they carried arms and ammunition.

The Brazilian national news agency EBN said the arms cargo on the U.S.-built Hercules cargo plane detained in Recife had been completely unloaded and the plane was expected to leave for an unidentified destination Sunday if engine repairs could be completed.

The three Soviet-made planes at Manaus Airport also were entered and searched "without difficulty," according to presidential spokesman Carlos Atila. The 38 Libyan crew members waiting in a hotel refused to watch the search, and it was not immediately clear if Brazilian officials had broken into the locked planes.

A description of the arms was not immediately available, and the origin of the arms reportedly had not yet been ascertained. A team of weapons experts was on the scene.

The agency said the planes were still parked close to the airport terminal and could not be unloaded until they were moved to a more isolated spot. The Libyan pilots had refused Brazil's request for cooperation, and the hydraulic mechanisms of the three planes were being studied so that they could be towed away from the terminal without damage.

All reporters were barred from Manaus Airport, which has been closed since yesterday and ringed with helicopter-borne commandos.

The searches were carried out without the presence of diplomatic representatives from Libya despite requests for their cooperation from Brazil.

Following an early and uncharacteristic apology from Libya's Col. Muammar Qaddafi, the diplomatic repercussions of the incident have strained Brazilian-Libyan ties. Libya yesterday summoned Brazil's ambassador in Tripoli for talks, and relations may be broken off.

There also are reports that Libya, one of Brazil's biggest arms customers, may turn elsewhere and cancel an order for 160 Tucano trainer planes. Oil supplies also could be affected.

Libya had warned Brazil that it could receive "a double surprise" when it opened the planes, which arrived at the northern Brazil airports Monday, and the Air Force minister has admitted that Brazilian-made weapons could be aboard.

Brazil has imposed end-use safeguards on arms sold to Libya since a missile it sold to Tripoli was used by the PLO against Israel in 1979. Arms sales have continued undiminished, however.