Beirut, Lebanon ? By air and on land, Israeli forces and Hezbollah fighters battled fiercely Sunday in a last-minute surge of bloodletting before an official cease-fire went into effect this morning.

Plumes of smoke were seen rising above the hills of the Lebanese port city of Tyre, and sirens warning of incoming rockets sounded across northern Israel minutes before the truce commenced at 8 a.m. local time (midnight Sunday CDT). Israeli artillery fire reverberated across the border, while an airstrike was reported in Lebanon’s Bekaa Valley less than two hours before the deadline.

The violence came amid signs of potentially serious snags in the Lebanese government’s implementation of the U.N.-brokered truce. On Sunday afternoon, after sharp debate, the Israeli Cabinet formally approved the United Nations resolution calling for a cease-fire.

Throughout the day and into the night, Israeli warplanes and gunboats hammered southern Lebanon, leveling buildings and bombing other infrastructure around the coastal city of Tyre. In south Beirut, just outside Hezbollah-controlled suburbs, 20 explosions were heard in the space of three minutes, which destroyed a complex of shops, apartments and offices less than an hour after the Israeli Cabinet voted to accept the cease-fire.

At least 22 people were reported killed in the various strikes.

Hezbollah guerrillas unleashed more than 220 rockets on northern Israel, one of the highest counts of the monthlong conflict. Several landed in Haifa, Israel’s third-largest city, where billows of black smoke rolled through blue sky. One person died in the daylong barrage.

The intensified fighting capped a weekend of some of the fiercest clashes in nearly five weeks of confrontation, after Israel widened its ground offensive in an eleventh-hour bid to clear out more Hezbollah fighters from southern Lebanon before the cease-fire.

Under the U.N. resolution, both sides were to halt attacks this morning, although Israel is allowed to defend its positions.

But troubling signs emerged Sunday as to how Lebanon, Hezbollah and Israel would interpret and implement the agreement, raising the possibility of a continuation of major fighting.

Amid internal feuding, the Lebanese Cabinet postponed a meeting to vote on implementing the cease-fire.

Although officials were reluctant to publicly describe the disagreements, a rift appeared to be developing over the disarmament of Hezbollah, which the resolution demands.

Interior Minister Ahmed Fatfat told Lebanese television that the Cabinet had given itself 48 hours to discuss how it would enact the cease-fire’s terms.

Although Hezbollah is obligated to stop military operations and lay down its weapons, Sheik Hassan Nasrallah, the organization’s leader, has warned that his fighters will continue their campaign against Israeli soldiers as long as the Jewish state maintains troops in Lebanon.

Israel, in turn, contends that its right to defensive action includes preventing efforts by Hezbollah to rearm, at least until the installation of a 15,000-strong international peacekeeping force, along with 15,000 Lebanese troops. Under the truce, Israeli troops, believed to number about 30,000, will leave the south only as those forces move in, which is days or weeks away.