(Adds police comment) BAGHDAD, Feb 26 (Reuters) - A blast at an Iraqi ministry during a ceremony attended by Vice President Adel Abdul-Mahdi killed six people on Monday but the vice president was unhurt, a ministry employee and police said. Police said six people had been killed and 31 wounded. The employee said he had seen four dead bodies. Two police sources said the blast happened inside a hall at the time Abdul-Mahdi, a Shi'ite leader, was at the Public Works Ministry building. As the employee spoke, the sounds of shouting could be heard in the background. It was unclear if the attack was an assassination attempt. The two police sources said it was unclear what caused the blast. Insurgents have increasingly been using suicide vests to carry out attacks because of tighter checks on roads aimed at reducing car bomb attacks. U.S. and Iraqi forces launched a security crackdown in Baghdad earlier this month.
