RASHAYA, Lebanon (AP) _ Helicopter gunships blasted fundamentalist Muslim guerrilla positions in the Syrian-controlled Bekaa Valley today, police said. They said it was an Israeli attack, but Israel denied involvement.

No casualties were reported in the raid, about a mile north of Israel's self-proclaimed ''security zone'' in southern Lebanon.

It followed a clash the night before in which guerrillas, whose identity was unclear, ambushed an Israeli patrol in Israeli-controlled southern Lebanon.

Also Friday, Muslim fundamentalists claimed they killed four members of an Israeli-supported Christian militia by shelling a militia barracks in retaliation for a previous attack.

Police said two Cobra helicopters rocketed and strafed positions of the pro-Iranian Shiite Hezbollah, or party of God, around the village of Qalia at 6:30 a.m. for more than an hour.

Police said it was an Israeli attack, but the Israeli military command in Jerusalem denied any involvement.

The Israeli command also said it was checking a Lebanese report that guerrillas attacked an Israeli patrol Friday night in the village of Kawkaba, just across the line of the security zone, touching off a 15-minute firefight.

Israeli gunners retaliated with an artillery barrage on the Bekaa villages of Zelaya, Qalia and Ein El-Tineh shortly before the air strike, a Lebanese police spokesman said.

The spokesman, who cannot be named in line with regulations, said Israeli troops in tanks and armored personnel carriers pushed into the Qalia area after the raid, searching for Hezbollah guerrillas.

Hezbollah's Voice of Islam radio station confirmed the raid on the party's positions around Qalia, but said the nighttime ground foray into the Israeli enclave was mounted by Palestinians, not by Hezbollahis.

The radio said, however, that on Friday night Hezbollah's positions had shelled the Rihan barracks in the Israeli-controlled Christian town of Jizzine, which is used by the Israeli-allied South Lebanon Army militia.

It claimed that four of the militia's men were killed and four wounded. There was no immediate comment from the militia on the claim.

''The Rihan operation was in retaliation for the Israeli shelling of several Bekaa villages last week,'' said the station.

Four children were killed and three people were wounded in the Israeli shelling on Dec. 29.

By police count, 40 people were killed and 82 wounded in 22 Israeli air strikes into Lebanon last year.

Israel maintains about 1,000 troops, with armor and artillery, in the six- to 10-mile-wide buffer zone carved out when the Israelis withdrew the bulk of their army from Lebanon in 1985, three years after it invaded.