BEIRUT, Lebanon (AP) _ Anti-aircraft fire struck President Amin Gemayel's private wing at the government palace Sunday as Christian and Moslem militias dueled along Beirut's dividing Green Line, police said.

Police said sniper fire shattered windows and pocked the concrete walls but did not injure Gemayel, 42, who was in another part of the palace when .50- caliber rounds struck shortly after midnight.

The palace is on a hilltop in suburban Baabda, five miles east of Beirut.

None of the staff or guards at the two-story building were injured, police said.

A police statement said three people were killed and 20 others wounded in artillery battles that engulfed more than 20 residential neighborhoods in Beirut and its suburbs.

The new casualties raised the overall toll in 22 days of sectarian fighting in Beirut to 117 killed and 602 wounded, by police count.

A police statement said several cars and apartments were set ablaze by shell fire and residents huddled in basements and bomb shelters through the night.

The statement said the combatants traded up to 4,000 rounds of rocket- propell ed grenades, Soviet-made rockets, mortars and recoilless gun rounds before the fighting dwindled to sporadic sniping at dawn.