Iraqi officials say two suicide bombings have killed at least 26 people in northern Iraq.

In the deadliest attack Thursday, officials say a bomber blew himself up at a police recruiting center, killing 16 people and wounding 14 others. Police and hospital officials in the northwestern town of Sinjar say 14 of the dead were police recruits, and the other two were police officers.

In Mosul, U.S. forces say a suicide bomber driving a police vehicle killed two Iraqi policemen and eight bystanders. Sixteen other people were wounded in that attack.

Separately, police say members of a U.S.-backed Iraqi neighborhood patrol killed at least 12 insurgents during a clash near the northern city of Tikrit.

Iraq's vice president, Adel Abdul-Mahdi, traveled to Tehran on Thursday, where he met with Iranian President Mahmoud Ahmedinajad and the newly-elected speaker of parliament, Ali Larijani, to discuss security issues. Iranian media say the men also discussed Tehran's concerns about a proposed U.S.-Iraqi security agreement, which would replace the current United Nations mandate for U.S. troops in Iraq.

In Mosul, U.S. forces captured 11 suspected al-Qaida militants. A U.S. military spokesman says one of the men is believed to be a senior al-Qaida in Iraq leader.

In other news, the families of five British men being held hostage in Iraq pleaded for their release in an interview with the BBC.

The Britons were seized from an Iraqi Finance Ministry building in Baghdad one year ago.

Britain's ambassador to Iraq, Christopher Prentice, also issued a call for their release to coincide with the anniversary of their kidnapping. He said the British government remains committed to working for the release of all hostages.