Gaza border heats up after West Bank violence

STORY: Smoke rises over Gaza after an Israeli strike on Thursday (February 23) morning.

Tensions flared there - as well as fears of a broader escalation - a day after an Israeli raid on Nablus in the occupied West Bank killed 11 Palestinians and wounded more than 100.

Palestinians went on strike across the West Bank, East Jerusalem and Gaza on Thursday. Schools, universities, shops and banks closed their doors.

Nafez Sider lives in Hebron.

"It is a day of mourning and a strike. How could we work or eat or drink while our brothers in Nablus are being killed? We had to stand in solidarity with them, with the people of Nablus, and there had to be a general strike in the whole West Bank and Gaza and thank God there is."

Israel's military said six rockets were fired from Gaza, setting off air raid sirens in southern Israel.

Five were intercepted and no injuries were reported.

Israeli fighter jets later struck a weapons manufacturing site belonging to Hamas, the Islamist group that controls Gaza, the Israeli military said. There were no known injuries.

This Israeli forces video shows the Nablus raid: soldiers firing on a house where they said militants were hiding.

Six gunmen and five civilians were killed, Palestinian sources said.

Egypt and the United Nations were mediating on Thursday to calm the situation, as U.N. Middle East envoy Tor Wennesland arrived in Gaza to meet Hamas leaders.

The Palestinian militant faction Islamic Jihad stopped short of claiming it fired the rockets from Gaza, but said it had the right to defend against Israeli aggression.

Leaders from Hamas and Islamic Jihad warned mediators that the situation could slide into an "open confrontation" if there was no change, according to a Palestinian official.

Israeli Prime Minister Benjamin Netanyahu's office declined to comment.