BEIRUT, Lebanon (AP) _ A Palestinian guerrilla group claimed it killed or wounded nine Israeli soldiers today after ambushing an Israeli patrol in south Lebanon. The Israeli army denied any of its soldiers were hurt.

Also today, three Israeli soldiers were wounded in a separate attack when explosions ripped through a tank and a military truck in south Lebanon, security forces said. There was no claim of responsibility in the blasts.

The Marxist-oriented Democratic Front for the Liberation of Palestine said it ambushed the Israeli patrol at 6 a.m. in a narrow valley near the village of Taibeh in Israeli's self-declared security zone.

''The Zionist enemy and its surrogates of the South Lebanon Army militia rushed tank-led reinforcements to the confrontation region in an effort to encircle our comrades, who had succeeded in wiping out the Israeli patrol,'' the Palestinian group said in its statement.

A later statement from the group sent to The Associated Press in Cyprus said nine Israelis were killed or wounded in the ambush and that the attack was in retaliation for an Israeli air raid Thursday on Palestinian targets in Lebanon. One man was killed and three people wounded in that raid.

The Israeli army said today's battle was ''not a major incident.''

A military statement said the Israeli soldiers ''came under light arms fire. Soldiers in the force sustained no casualties and returned fire at the source of the shooting.''

In the southern village of Barachit, also in the security zone, an Israeli soldier was wounded when a mine went off near his tank, the Israeli army and Lebanese security sources said. Israel radio said the officer was slightly wounded.

Five hours later, a mine went off under an Israeli military truck near Barachit, wounding two Israeli soldiers, a security source in Lebanon said. The source said the victims were evacuated by helicopter to Rambam hospital in Israel's northern port city of Haifa. Their conditions were not known.

Israel has controlled the security zone, a strip of land six to 10 miles wide along the border, since its invasion of Lebanon in 1982. It kept the area as a buffer against border attacks when it withdrew most of its army in 1985.