Eighteen people were killed and 21 others injured Friday when two bombs were detonated at a Sunni Muslim mosque in Samarra, north of this capital, Iraqi police sources told Efe.

The attack targeted worshippers attending Friday prayers at the Musab bin Omair mosque, which was badly damaged in the explosions.

Some of the wounded are in critical condition and the death toll could rise, the sources said.

The deadly strike came hours after leaders of most of Iraq's political parties signed a pact of "honor and social peace" to confront a resurgence of sectarian violence.

The document, which calls for political differences to be settled consensually and for a crackdown on armed militias, was endorsed by Prime Minister Nuri al-Maliki, Vice President Khodair al-Khozaei and parliament speaker Usama al-Nujayfi, among others.

More than 800 people died last month in Iraq as a result of political or sectarian violence, bringing the civilian death toll for the year so far to around 5,000, the U.N. mission in Baghdad said. EFE