Suicide bomber kills 28 in Baghdad-police

(Updates toll)

BAGHDAD, April 23 (Reuters) - A suicide bomber wearing a vest stuffed with explosives blew himself up in a group of police distributing relief supplies in Baghdad on Thursday, killing at least 28 people and wounding 50, Iraqi police said.

The police were helping to pass out aid to Iraqis who had been driven from their homes during the sectarian bloodshed and insurgency unleashed by the 2003 U.S.-led invasion.

At least five children were among the dead, police said.

Violence across Iraq has fallen sharply over the past year but insurgents such as al Qaeda still carry out frequent attacks. Suicide bombings are often associated with al Qaeda.

A suicide bomber on Wednesday killed at least five people and wounded 15 inside a mosque in central Iraq, and on Monday, a suicide bomber in a police uniform killed four policemen in northeastern Diyala province. Eight U.S. soldiers were wounded.

Some expect violence to increase as rival political and armed groups position themselves ahead of a national election due to take place at the end of the year. (Editing by Michael Christie)