Palestinian medics say a blast in the Gaza Strip has killed an important member of the Islamic Jihad militant group and six other Palestinians.

The Friday night explosion destroyed the home of the Islamic Jihad commander, Ayman al-Fayed, and damaged nearby homes in the Bureij refugee camp near Gaza City. Medics say the militant's wife and two of their children are among the dead. About 40 other people were wounded.

Islamic Jihad and witnesses blamed the explosion on an Israeli missile strike, but the Israeli military denied involvement.

In other news, the top United Nations humanitarian affairs official, John Holmes, visited Gaza Friday and says he was shocked by the misery he says has been caused by Israel's closure of the border. He is calling for the crossings to be opened so the people of Gaza can get food, power and other essential supplies.

Israel has blockaded the Gaza Strip in an effort to pressure Palestinian militants to halt rocket fire into Israel.

An opinion poll released in Israel Friday shows that 67 percent of Israelis support a large-scale ground operation into Gaza to stop Palestinian rocket attacks.

The Israeli government has been reluctant to invade the heavily populated Palestinian territory, but Israeli Defense Minister Ehud Barak says he has ordered the army to prepare for a possible offensive against Hamas, the Islamic militant group that rules Gaza.