GAZA CITY, Gaza Strip - Israel fired missiles at five Hamas targets just minutes apart Saturday, killing four people hours after Gaza militants floated the idea of halting rocket fire on Israeli border towns if Israel ends its 10-day-old air campaign.

After the attacks, Hamas said a truce was no longer being considered.

In all, Israeli aircraft launched 11 missile strikes Saturday. Before dawn, they struck near the house of Prime Minister Ismail Haniyeh of Hamas in a Gaza refugee camp, while troops in the West Bank arrested a Hamas Cabinet minister.

Israel's offensive is aimed at halting Hamas rocket fire from Gaza at Israeli border towns.

Since last week, dozens of targeted missile strikes have killed nearly 50 Palestinians and damaged many Hamas installations. Israel said some 225 rockets have landed in Israeli towns since May 15, killing one woman and sending thousands of frightened Israeli residents fleeing. One rocket landed in Israel on Saturday.

Moderate Palestinian President Mahmoud Abbas has tried in recent days to revive a truce with Israel. Under his plan, Gaza militants would halt rocket fire for a month to allow for negotiations on a more comprehensive cease-fire that would include the West Bank.

After a meeting late Friday, the militant groups initially asked for 48 hours to respond to the proposal. Abbas has been in talks with them since Tuesday.

However, Hamas hardened its stance after Saturday's rash of air attacks, including five in less than an hour, calling on militants to "direct painful strikes at the Zionist enemy." In a statement, the group said it "will not offer a free truce to the Zionist occupation."

One of the attacks hit a key Hamas base in Gaza City, killing four Hamas members and wounding five.

The compound was used as a training center and base for Hamas' militia, the Executive Force. Two rooms in the camp were destroyed and rescue workers searched the rubble. A nearby charity was badly damaged from the strike. Hamas gunmen shot in the air to disperse a crowd of onlookers.

Earlier Saturday, two missiles hit close to Haniyeh's house in the Shati refugee camp on the outskirts of Gaza City. One landed around 90 metres away and the other 270 metres away, hitting trailers used by Haniyeh's bodyguards.

The missiles left two large craters, shattered surrounding windows and cut electricity in they crowded camp. No injuries were reported.

The army confirmed the Shati strikes but said Haniyeh was not a target. However, earlier this week, Israel's deputy defense minister had warned that none of the Hamas leaders are immune.

Haniyeh stayed away from public prayers on Friday. He issued a statement after the second strike saying the air strikes in Gaza are a sign of Israel's "political and security crisis."

"This campaign will fail because of the steadfastness of the Palestinian people," Haniyeh said.

In the West Bank, Israeli troops arrested Cabinet minister Wasfi Kabaha, confiscating his computer and many of his documents. The arrest came two days after a sweep in which more than 30 Hamas politicians, legislators and local council members were arrested, including the education minister.