Israel stepped up its offensive against militants in the Gaza Strip on Sunday by launching more attacks, including strikes on the homes of two Hamas men that resulted in the deaths of eight Palestinians.

One attack hit the residence of Khalil al-Haya, a senior Hamas lawmaker in Gaza City's Sejaiyeh quarter, where family and relatives had gathered. Of the dead, six were civilians, including al-Haya's family members, and two were militants, Hamas's armed wing said.

Hamas lawmaker Khalil al-Haya, centre, visits Shifa Hospital's morgue to view family members killed in an Israeli missile strike in Gaza City on Sunday.
(Adel Hana/Associated Press)

Al-Haya, who was not home at the time of the attack that also wounded 13, was not the intended target, the BBC reported, citing Israeli defence force officials. Gunmen standing outside his home were the intended targets, they said.

Another attack targeted the home of a Hamas militant in Beit Lahiya, wounding him and four of his children.

In the past week, dozens of rockets have landed in Israel, mostly in the community of Sderot, wounding seven people. Palestinian militants fired five more rockets into Sderot on Sunday morning. No one was reported killed or seriously injured in the latest attack.

Since Tuesday, Israeli forces have killed 35 Palestinians in at least 22 air strikes, including one launched before dawn on Sunday against what Israel said was a Hamas rocket squad.

"Hamas people are paying, and will pay, a very heavy personal price for these attacks on the residents of Sderot and nearby communities," Prime Minister Ehud Olmert said Sunday in Jerusalem.

Olmert said the military would be forced to "intensify" its response in Gaza if Palestinian militants continued the attacks.

Israeli army officials said Sunday's pre-dawn air raid killed three people in a car who were suspected of being Hamas militants.

They said their planes also destroyed an arms factory belonging to two Palestinian militant groups.

Channel 2 TV in Israel said an intensification in Israel's actions against Gaza would include targeting Hamas militant leaders and sending Israeli commandos into Gaza to hit rocket squads, but the Israeli government had no immediate comment.

With files from the Associated Press