At least one Palestinian gunman infiltrated a Jewish settlement in the Gaza Strip in the early morning hours Friday, killing three Israeli soldiers and wounding two others. Members of the militant groups Islamic Jihad and Hamas have claimed joint responsibility for the attack.

Israeli authorities say the gunman cut through a fence, entered the heavily guarded settlement of Nezarim and opened fire. Two of the soldiers killed were women.

Troops shot and killed one gunman. There are reports another militant may have been on the scene and escaped.

In a separate incident Israeli troops are reported to have shot and killed a Palestinian they say approached the security barrier of another Jewish settlement in northern Gaza.

And late Thursday, Israeli troops shot dead a Palestinian gunman who fired at a car and lightly injured three Jewish settlers in southern Gaza.

The militant group Hamas says one of its members, Samir Fouda from the Jabalya refugee camp, carried out Friday's attack on Nezarim in coordination with the military wing of Islamic Jihad.

The two groups declared earlier this week they will strengthen cooperation, and militants have vowed to step up their attacks after Israeli air strikes in the Gaza Strip Monday killed more than 10 Palestinians, including militants and civilians.

Friday's violence also follows an announcement by Israel that it is seeking bids to build more than 300 new apartments in two Jewish settlements in the West Bank, despite provisions in an international peace plan against such action. Jewish settlements in the West Bank and Gaza Strip are one of the main issues of contention in the Israeli-Palestinian conflict.

Tension has also escalated in recent weeks over Israel's continued construction of a security barrier around the West Bank. Israel says the barrier is necessary to stave off terrorist attacks. Palestinians and other critics say it's an Israeli attempt to grab as much Palestinian land as possible and create de-facto conditions on the ground prior to any future negotiations.

The United States is opposed to unilateral measures by either side on matters that should be negotiated in a peace agreement. Washington has also criticized Israel's continued settlement activity and expressed concern over the route being taken by the security barrier in Palestinian areas.

However, the United States voted against a U.N. General Assembly Resolution this week, which condemned the barrier and demanded that Israel halt the project and dismantle those parts of the barrier which are on Palestinian land.