As hunt for bin Laden continues, U.S. rebukes Israeli assassinations

Boucher's comments came after Israeli soldiers on Sunday shot and killed Abed-Rahman Hamad, a Hamas leader accused of dispatching the suicide bomber who carried out the June 1 attack outside a Tel Aviv disco that killed 21 Israeli youth.

Hamas vowed that "Israel will pay a very heavy price for this act."

Hamad had been arrested by the Palestinian Authority in June, but was released in August.

Also on Monday, a Hamas militant was killed in an explosion in the West Bank city of Nablus. Palestinian officials said Israel was behind the death of Ahmed Marshoud, but Israel had no immediate comment.

Meanwhile, two other recent deaths are being investigated by Palestinian officials, both of which Israel denies involvement in.

An explosion in the Gaza Strip killed Iyad Ahras, 28, of the Popular Resistance Committee, a group of gunmen from various Palestinian factions who frequently battle with Israeli soldiers stationed in Gaza. Officials said they were looking into the possibility the incident could have been a "work accident" that took place while Ahras was preparing a bomb for an Israeli target.

The remains of another Hamas militant were found Oct. 11 in the West Bank. Doctors said they could not determine whether Hani Rawajbeh, 22, was killed while preparing a bomb or by a tank shell.