Leftist rebels shot down a Salvadoran air force jet Friday, the government said, apparently the first time the guerrillas have successfully used an anti-aircraft missile in El Salvador's long civil war.

The A-37 attack jet's pilot was killed when the aircraft was downed by a missile at 1:45 p.m. in Uslutan province in the eastern section of the Central American country, the government said in a statement broadcast on national radio.The Farabundo Marti National Liberation Front (FMLN) rebels did not issue a statement on the aircraft's downing.

Although the rebels have acknowledged possessing Soviet-designed SA-7 missiles, popularly known as SAM-7s, it has so far never used them to down an air force plane or helicopter, military analysts say.

The rebels launched a nationwide series of military attacks Monday night, which have claimed at least 90 lives and wounded some 300 people.

"The FMLN (rebels), during the last 72 hours, have been using sophisticated war devices, such as SAM-7 and SAM-14 ground-to-air missiles," the government said in a statement broadcast on national radio.

"These constitute extremely dangerous actions that could affect the country's political stability," the statement said.