Jerusalem ? A British human rights activist released by Gaza kidnappers said Saturday she would stay in the region despite threats by militants to seize more foreigners, as Palestinian leader Mahmoud Abbas warned the growing lawlessness is hurting economic development and statehood aspirations.

Abbas also said the chaos would not derail parliament elections set for Jan. 25.

However, the Palestinian leader has been unable to impose order, particularly in Gaza, where dozens of armed groups affiliated with his Fatah Party have seized hostages, stormed public buildings and attacked police stations in recent months – either to press demands for government jobs or to settle personal feuds.

In one incident Saturday, gunmen demanding jobs briefly seized a government building in the central Gaza town of Deir el Balah. Another group of armed men, including off-duty police, set up an impromptu roadblock near the Gaza-Egypt border, threatening to prevent VIPs from crossing, as part of a fight between police and a local clan.

Late Saturday, two Palestinians were killed in an Israeli air strike in northern Gaza, Palestinians officials said, the first deadly attack there since Israel declared a “no-go” zone on Sunday to try to stop Palestinian rocket barrages. Israel began enforcing the ban Wednesday.

Relatives of two Palestinians killed by an Israeli airstrike wait late Saturday at the hospital of the northern Gaza Strip town of Beit Lahiya. Two Palestinians were killed Saturday in an Israeli air strike in northern Gaza, Palestinians officials said, the first deadly attack since Israel declared a no-go zone.

Relatives said the two were members of the same family, and one was with Palestinian security. The Israeli military said the air force hit a cell of Palestinians preparing to fire a rocket.

The Palestinian Interior Ministry issued a statement condemning the Israeli strike, saying a shell hit a Palestinian post, hindering police efforts to stop militants from firing a rocket at Israel.

Hamas spokesman Mushir al-Masri, talking to reporters at the hospital where the casualties were taken, threatened revenge against Israel. However, he did not rule out extending a truce declared in February. The truce formally expired at the end of the year, Saturday night.

Briton Kate Burton, 25, and her parents, Hugh and Helen, were freed in Gaza late Friday. In a statement issued Saturday, the Burtons said they were treated “extremely well” during their ordeal, and they asked to be “left in peace to recover with close friends and relatives.”

Hugh and Helen Burton were to leave for Europe over the weekend, British officials said.

Kate Burton said she “plans to stay in the region and continue working with the Palestinian people.” She is expected to return to Gaza within several days to resume working for the group Al-Mezan, said its head, Kamal Sharafi.