UNITED NATIONS - Israel's shelling of the Lebanese village of Qana appears to fit a pattern of violations of international law marking warfare between Israel and Hizbollah guerrillas, U.N. Secretary-General Kofi Annan said on Monday.

A girl holds a poster of child killed in the southern Lebanese town of Qana, during a protest in Amman August 3, 2006, against the Israeli air strikes on Lebanon and Gaza Strip. [Reuters]

In a report to the U.N. Security Council, Annan said a comprehensive investigation was needed to gather evidence of possible violations of international humanitarian and human rights laws affecting both Lebanese and Israeli civilians during the conflict.

The 15-nation council asked Annan to look into the deadly July 29 Israeli bombing of a residential building in Qana to determine the facts of the raid, which triggered outrage around the world.

Early Lebanese reports on the attack branded it a massacre, putting the death toll at more than 54 people and at one point more than 60 people.

A Security Council statement adopted a day after the bombing expressed "extreme shock and distress" at the shelling and called for a U.N. inquiry to be completed within a week.

The Lebanese government later said it had found 28 corpses, some 14 of whom were children, but it added the toll could still rise as recovery efforts had been temporarily suspended.

Israel said in an August 3 letter to Annan that it regretted the civilian casualties but "blames Hizbollah for manipulating and using innocent Lebanese civilians as human shields."

The Lebanese government, however, told the U.N. chief that rescuers found no weapons in the building and no evidence that any of the dead had been Hizbollah militants.

Lebanese military authorities found "no indication that rockets were launched next to the building," it said.

Annan said a week was inadequate to determine the facts.

"The attack should be seen in the broader context of what could be, based on preliminary information available to the United Nations, including eyewitness accounts, a pattern of violations of international law ... committed during the course of the current hostilities," he said.

"The effects of the current conflict on civilians in Lebanon and Israel rise to a level of seriousness that requires further gathering of information including violations of international humanitarian law and international human rights law," he said.

"Accordingly, I support the calls for a more comprehensive investigation," he said.