BAGHDAD — A wedding celebration turned deadly Wednesday when a bomb hidden in a plastic bag killed three people and wounded 18 in a town south of the Iraqi capital, police and hospital officials said

Details were sketchy after the attack on a Sunni tribe in Musayyib, about 40 miles south of Baghdad. The blast was a reminder of the daily deadly violence that continues to dog Iraq, though attacks have dropped dramatically nationwide from just a few years ago.

The police and hospital officials spoke on condition of anonymity because they were not authorized to release the information.

The attack came hours after a Kurdish imam was reported kidnapped in the northern city of Kirkuk, which is a longtime simmering pool of ethnic tensions.

Kirkuk Police Chief Maj. Gen. Jamal Tahir said officials suspect Imam Abbas Hadi was taken from his home late Tuesday because his brother is a Kurdish intelligence police sergeant. He denied that Hadi had been arrested by security forces, although some residents say the imam’s mosque had been repeatedly searched.

Tahir, a Kurd, said Hadi is also a vocal supporter of the government in Iraq’s semiautonomous Kurdistan region — an issue that would draw the ire of Arabs in Kirkuk. Kurds and Arabs have long struggled for control of the city and the lucrative oil reserves beneath its soil.

Also Wednesday, an Iraqi government spokesman said Baghdad is stepping up efforts to curb weapons smuggling from its territory into Syria as President Basher Assad’s regime struggles with violent demonstrations.

Iraq for years has accused Syria of turning a blind eye to al-Qaida weapons and fighters streaming across its northern border to assist Iraq’s Sunni-led insurgency.

But Syria now says deadly traffic is coming from Iraq.

Iraqi spokesman Ali al-Dabbagh said security committees are working on preventing any trafficking of weapons and militants between the two countries.

He acknowledged “infiltrators from both sides” — an unusual admission by Baghdad that Iraqi fighters are hurting Syria’s security.

Rights groups say more than 1,000 people have been killed in the crackdown on Syria’s uprising.

Associated Press writer Qassim Abdul-Zahra contributed to this report.