GAZA, Jan. 10 (Xinhua) -- Three Palestinians were killed in an explosion in Central Gaza Strip town of Deir al-Balah late on Sunday, medical sources and witnesses said.

    The witnesses said that a group of Palestinian militants were about to fire rockets into Israel from the east of the town when a powerful blast rocked the area.

Palestinians mourn after three Gaza militants were killed in an Israeli missile strike, in the central Gaza town of Deir al-Balah, Jan. 10, 2010

The Israeli army told Xinhua it was checking if the explosion was a result of an Israeli attack on the fighters.

    Hospital officials said a fourth gunman was seriously injured.

    Meanwhile, security sources said an Israeli missile has hit the group shortly after they have fired the first rocket into an Israeli target beyond an electric fence that marks the borderline.