GAZA CITY: An Israeli air strike on Rafah in southern Gaza killed four people on Saturday, Palestinian medics said, raising the overall death toll from the aerial campaign to 38.

The attack came as the Tunisian foreign minister crossed into southern Gaza through the Rafah border crossing with Egypt.

It followed hot on the heels of other strikes elsewhere in the city which killed one, and a raid on a refugee camp in central Gaza which killed another three, medics said.

“Four people were killed in a third raid on Rafah that targeted a group of citizens in the Zuhur neighbourhood,” said Adham Abu Selmiya, spokesman for Gaza’s Hamas-run emergency services.

Meanwhile, similar air strikes destroyed the cabinet headquarters of Gaza’s Hamas rulers.

“The IDF (army) has targeted Ismail Haniya’s headquarters in Gaza,” an Israeli army spokesman told AFP, referring to the Hamas prime minister.

Haniya’s government said four “barbaric Israeli” strikes “completely destroyed” its headquarters and that neighbouring houses were damaged.

Witnesses said the damage was extensive but there were no reports of casualties.

The latest strikes raised the overall death toll in Gaza to 38 as a relentless Israeli air campaign against Gaza militants entered its fourth straight day.

The identities of the four killed in the latest Rafah strike were not immediately clear.

Earlier, medics said three people had been killed in Maghazi refugee camp in central Gaza and another man had died in a raid on Tel al-Sultan neighbourhood in Rafah.

“Three men died in an Israeli air strike on Maghazi camp in central Gaza,”said emergency services spokesman Adham Abu Selmiya.

Palestinian security sources told AFP that all four were Hamas militants.

They named the three who died in Maghazi camp as Ali Manameh, Hossam Abdel Jawad and Assaf Gharwish, while the man who died in Rafah was Mukhlis Adwan.

Potential ground war

The Israeli military earlier said it had sealed off all the main roads around the Gaza border, declaring the area a closed military zone, as it called up thousands more reservists in readiness for a potential ground war.

UN and Palestinian officials said UN chief Ban Ki-moon would travel to the region in days to push for a truce.

“Ban went to the region during the last Israeli offensive against Gaza in 2009 and worked hard to end that conflict. He is looking to produce a truce and ceasefire this time as well,” one senior UN diplomat said.

Even before the latest rocket fire, senior cabinet minister Moshe Yaalon warned that Israel was poised for a ground offensive.

“We are preparing all the military options, including the possibility that forces will be ready to enter Gaza in the event that the firing doesn’t stop,” he said.

As ground troops massed, there was no let-up in Israeli air attacks.

The overthrow early last year of veteran strongman Hosni Mubarak, a staunch supporter of Egypt’s three-decade-old peace treaty with Israel, has cast a chill over the already lukewarm relationship between the two neighbours.

Egypt’s new President Mohamed Morsi, who like Hamas has his roots in the Muslim Brotherhood, has moved to establish closer relations with the Gaza authorities.

Washington appealed to Egyptian leaders as well as to allies such as Turkey to use their sway with the Palestinians in a flurry of telephone diplomacy aimed at containing the crisis.

In Obama’s call to Netanyahu, the president “reiterated US support for Israel’s right to defend itself, and expressed regret over the loss of Israeli and Palestinian civilian lives”, the White House said in a summary of the conversation.