The Islamic Jihad militant group claimed responsibility for the ambush.

Elsewhere, Palestinian medics said an Israeli attack in northern Gaza killed a Palestinian militant.  Israel has not commented on the incident.

The new violence follows a visit to the region by U.S. Secretary of State Condoleezza Rice, who secured pledges from Israeli and Palestinian leaders to resume peace talks.

Palestinian President Mahmoud Abbas had suspended the talks on Sunday to protest an Israeli offensive in Gaza that killed more than 120 Palestinian militants and civilians.

In other news, a coalition of British aid groups says the humanitarian situation in the Gaza Strip is the worst since Israel first occupied the territory more than 40 years ago.

In a new report released Thursday, eight British-based rights organizations called for the end of the Israeli blockade on Gaza, saying the measures taken are illegal under international humanitarian law. The aid groups, including Amnesty International and Oxfam, said the blockade has dismantled the economy and impoverished the population.

According to the report, about 80 percent of Gaza's residents are dependent on food aid, as opposed to 63 percent in 2006.  It also said the overall unemployment rate is nearly 40 percent.

The agencies urged Palestinian armed groups to stop "indiscriminate rocket attacks" on southern Israel and the Israelis to end "disproportionate attacks" in Gaza.

They also encouraged negotiations with Hamas, the Islamist group that seized control of Gaza last June and is considered a terrorist group by the United States, EU and Israel.

Some information for this report was provided by AFP, AP and Reuters.