Annan cited on Saturday reports of the frenzied demolition "of scores of buildings in the Rafah refugee camp over the last two days, in addition to 130 residential buildings already destroyed this month."
"The secretary-general has repeatedly called on the government of Israel to address its security needs within the boundaries of international law," UN spokesman Fred Eckhard said in a statement on Saturday.
"He urges Israel to uphold its obligations as an occupying power by immediately halting such actions, which are tantamount to collective punishment and a clear violation of international law," Eckhard said.
The statements came shortly before Israel's Supreme Court imposed a temporary ban on the demolitions to halt Israeli army plans to raze dozens more houses to widen the corridor it controls on the border with Egypt.
The injunction, sought by a Palestinian rights group, was issued after troops had already destroyed more than 80 homes in Rafah in southern Gaza during an invasion in which seven soldiers were killed.
Judges were due to discuss the issue on Sunday.
The UN Relief and Works Agency (UNRWA) said the army had destroyed nearly 90 buildings, leaving more than 1000 people homeless.
"On entering the camp this morning, we found 88 buildings demolished which had housed 206 families. It affects 1064 people," said spokesman Paul McCann.
Palestinians carry their belongings
after Israel demolished their house
"It is probably one of the worst days of the Intifada for Rafah which has already been hit very hard," McCann told reporters.
The body of a Palestinian was found under the rubble of his Rafah home after it was demolished by the army, security sources said.
The Israeli army did not give a figure for the number of houses it had razed, but a spokeswoman claimed troops had demolished only houses which were being used as cover by fighters.
"We only destroyed houses after we were attacked by people
hiding in them," she said, adding that some houses may have been damaged in the violent clashes in the city over the past two days.
UNRWA has said that more than 11,000 people have been made homeless in Rafah through house demolitions during the Intifada.
Meanwhile, an Islamic Jihad leader, Muhammad al-Shaikh Khalil escaped an assassination attempt by Israel after a helicopter fired missiles at a property on Yibna in the southern Gaza Strip, Aljazeera's correspondent in Gaza reported.
The attack caused unknown casualties, the correspondent said.
Palestinian wounded after a
failed Israeli assassination attempt
The army made no comment on the attempt to hit Khalil, saying instead it had destroyed an explosives lab belonging to the group.
"The explosive lab of the Palestinian Islamic Jihad in Rafah served as a key centre for planning terrorist activities as well as the production of weapons," it said in a statement, adding that it was used for storing weapons smuggled under the border with Egypt.
"This is the third structure, used as a main focal point for
terrorist activity which was targetted by the IDF on May 15 in the Gaza Strip," it said, naming the other two targets in Gaza City as "a guise for recruiting and activating terrorists."
Two earlier strikes, which took place before dawn, targeted Islamic Jihad leader, Muhammad al-Hindi, Palestinian security sources said.
The failed assassination attempts came after a week in which 13 Israeli soldiers were killed in Gaza, most of them in two deadly attacks claimed by Islamic Jihad.
In the first strike, a helicopter fired three missiles at a building housing the group's headquarters, destroying the three-storey edifice in Gaza City's al-Rimal quarter, they sources said. Five people were wounded, but al-Hindi was not among them.
"On entering the camp this morning, we found 88 buildings demolished which had housed 206 families. It affects 1064 people"
A second strike hit al-Hindi's home in the city's al-Nasir district, slightly injuring a dozen people and damaging the offices of an Islamic Jihad charitable organisation in the same building.
Elsewhere in Rafah, two Palestinians were injured when Israeli
troops opened fire in Salah al-Din area, Palestinian medics told reporters, saying a 45-year-old man was in critical condition.