JERUSALEM, Sept. 29 (JTA) — A Hamas militant was killed and two others wounded when a car rigged with explosives blew up prematurely near the West Bank town of Ramallah. Israel has been bracing for Hamas terror attacks in the wake of threats of retaliation from the movement’s leaders for the Sept. 10 killings by Israeli troops of two Hamas militants, brothers Imad and Adel Awadallah. Coinciding with Tuesday’s explosion, Israel imposed a closure on the West Bank and Gaza Strip until the end of Yom Kippur. There have been several previous incidents in which Hamas militants were killed by the explosives they were apparently planning to use against Israeli targets. Tuesday’s explosion in the Ramallah suburb of Beitunia occurred not far from where the body of Hamas’ chief bomb-maker, Mohiyedine Sharif, was found last spring after a car explosion. The circumstances of Sharif’s death remain unclear. Hamas blamed Israel, which denied the accusation. The Palestinian Authority said Sharif had been killed in a Hamas power struggle and pointed the finger of blame at the Awadallah brothers. Tuesday’s explosion killed Hamas activist Zahran Ibrahim Zahran, according to Palestinian security officials, who said the car had been rigged with large amounts of explosives. The two injured men were taken to Ramallah Hospital, where they were placed under police guard, the officials said.