A suicide bomber in Iraq has killed at least 15 people at a police recruitment center in Fallujah.

Officials say the bomber blew himself up in a crowd outside the center Wednesday. At least 20 other people were seriously wounded.

In Baghdad, officials found 14 bullet-riddled bodies in addition to the 20 found late Tuesday. To the south, the British military says a roadside bomb killed an American contractor near Nasiriyah.

The violence came as Iraq's parliament held a brief working session. But lawmakers put off forming a committee to examine constitutional changes until after a cabinet is put in place. Prime Minister-designate Nouri al-Maliki has until May 21 to submit a cabinet for approval.

Sunni Arab politicians want to revise several provisions in the constitution, including one that allows the formation of regional governments. Sunni officials fear that would give Shi'ites and Kurds too much control over Iraq's oil.

Some information for this report was provided by AFP and Reuters.