UNITED NATIONS, April 13 (Reuters) - The U.N. Security Council denounced on Friday a suicide bombing that tore through the Iraqi parliament and demanded that those using violence against the political process in Iraq lay down their arms. A statement by the Council's current British presidency condemned "in the strongest terms" Thursday's "heinous act of terrorism" and expressed condolences to victims, their families and the people and government of Iraq. The bombing killed a member of parliament and wounded two dozen other people. An al Qaeda-backed group claimed responsibility for the worst breach of security in Baghdad's Green Zone, which also houses government offices and embassies. "The Security Council demands that those who use violence in an attempt to subvert the political process must cease hostilities, lay down their arms and participate in that process," the statement said. Since the 2003 U.S.-led invasion of Iraq, by even the most conservative estimates tens of thousands of people have died in bombings and shootings, clashes between insurgents and coalition forces and sectarian violence between Iraqi groups.