For the fourth consecutive day, troops of the 4,500-man multinational peace-keeping force were involved in shooting incidents as the French contingent was attacked by grenades before dawn today.

A French military spokesman said none of the 30 French troops on duty at a position in the Moslem suburb of Chiyah was wounded when a lone assailant threw two grenades. Only one exploded, and the attacker escaped under cover of darkness after the French opened fire.

Maj. Gen. Ibrahim Tannous, commander of the Lebanese Army, was quoted as accusing non-Lebanese parties of "masterminding" and "staging" the attacks to drive the American, British, French and Italian troops out of Lebanon. State-run radio and television reported his remarks, made at the presidential palace to a meeting of ambassadors from the four troop-contributing nations.

However, no tangible proof has been produced linking the attacks with any specific groups. The attacks began Tuesday against the Italian contingent and were followed by an incident involving the U.S. Marines.

In Lebanese eyes, possible suspects in the attacks range from the Israelis, out to prove that their troops' presence in Lebanon is necessary to preserve law and order, to "stay behind" Palestinian guerrillas and their leftist Lebanese allies, to pro-Iranian Shiite Moslems out to discredit the Lebanese government and its western friends.

[Meanwhile in Beirut, former President Jimmy Carter yesterday met with Lebanese President Amin Gemayel and later called for immediate withdrawal of Israeli troops from Lebanon, United Press International reported.]

[Carter said it was his "understanding" after talking to officials during his 17-day Middle East tour that if Israel withdrew, Syrian and Palestine Liberation Organization forces would follow suit.]

Carter said he hopes the Israeli occupation of the West Bank of the Jordan River "would not be repeated in Lebanon," The Associated Press reported.

Carter told a news conference that the longer the talks by the United States, Israel and Lebanon continued, the more difficult an actual pullout would be.