Muslim insurgents rejected on Monday a cease-fire offer by Afghan President Najibullah, saying it was a ploy to present himself as a religious man and gain favor among Muslim countries.

Najibullah offered last week to stop the fighting during the Islamic holy month of Ramadan, which began Sunday in Afghanistan. During Ramadan, devout Muslims fast from sunrise to sunset."It's just a cheap tactic to trick . . . Muslim countries," said Minhaj, a spokesman for the government-in-exile set up by the guerrillas.

He said Najibullah "has started this big campaign to show himself as a Muslim, but we know him for what he is - a communist."