* bodies found in West Bank field * Israel blames Hamas for abduction * Netanyahu convenes security cabinet * Obama condemns killings, urges restraint By **ah Browning and Ali Sawafta HEBRON, West Bank, July 1 (Reuters) - The bodies of three missing Israeli teenagers were found in the occupied West Bank, and Israel vowed to punish Hamas, the Palestinian group it accuses of abducting and killing them. "They were kidnapped and murdered in cold blood by beasts," Prime Minister Benjamin Netanyahu said in a statement after the military discovered on Monday the remains of the Jewish seminary students who disappeared on June 12.