At least 18 Palestinians, including five boys under the age of 16 and a 6-month-old baby, were killed in the Gaza Strip and two in the West Bank on Thursday during fighting with Israeli forces. Meanwhile, militants in Gaza continued to fire rockets at southern Israel, striking as far north as Ashkelon.

The targets of Thursday's air strikes included a police roadblock 150 meters from the Gaza City home of Hamas Prime Minister Ismail Haniyeh, in what appeared to be a message to Hamas.

The deaths come a day after IDF troops killed 12 Palestinians in Gaza fighting and an Israeli college student was killed in a Qassam rocket strike outside Sderot. Prime Minister Ehud Olmert vowed that Israel's response to the deadly barrage of Qassam rockets would be particularly harsh.

In the West Bank, IDF troops conducting arrests of terror suspects shot and killed a militant from the PRC and a member of the Fatah-linked Al-Aqsa Martyrs' Brigades in the Balata refugee camp, on the outskirts of Nablus.

Palestinian officials said one person was killed and four others were wounded in the attack near Haniyeh's home, which took place a day after the IAF targeted Haniyeh's empty office. Haniyeh - who has been in hiding for several weeks, fearing Israeli assassination - was not believed to be in the area. Israel has threatened to begin targeting Hamas leaders because of the ongoing rocket fire from Gaza.

Four Palestinians were killed in separate IAF attacks on an electric company vehicle in Khan Yunis that Israel said was carrying militants, and a truck said to be carrying canned beverages. The men who were pulled out of the charred vehicle were wearing military-style uniform, witnesses said, and the Israel Defense Forces said the truck was laden with rockets ready for launching.

Five children - all under the age of 16 and three from the same family - were killed in an IAF strike in Jabalya, a refugee camp in the northern Gaza Strip, Palestinian sources said. Witnesses said the children were playing soccer when the missile struck.

At least five Hamas militants, including the son of a senior Hamas lawmaker, Khalil al-Haya, and two PRC militants were killed in several attacks in northern Gaza and Gaza City. Al-Haya is one of Hamas' top figures in Gaza, and has himself escaped assassination attempts, including an IAF strike that killed his brother last year. Hamas said his son had commanded a rocket-launching squad in northern Gaza.

Visiting the morgue at Gaza City's Shifa hospital Thursday, al-Haya said he was proud that his son had lost his life for the Hamas cause, like many of his relatives.

"I thank God for this gift, he said. This is the 10th member of my family to receive the honor of martyrdom."

Overnight, IAF jets blasted a government building in Gaza. Palestinian health officials said a 6-month-old baby was killed in the attack, and 30 people were wounded.

Witnesses said the building was empty. The IDF said all targets that were attacked were centers of terrorist activity.

Palestinian militants fired some 30 Qassam rockets at southern Israel on Thursday, lightly wounding two people. Militants also launched 11 Grad rockets at Ashkelon, one of which scored a direct hit on a home in the port town. Several people were treated for shock.