Samarra - A car bomb mistakenly went off in a militant compound north of Baghdad Monday, killing 21 insurgents including a suicide bomber, an anti-Qaeda militia leader and a police officer said.
The group were filming a propaganda video of the would-be suicide attacker when a technical glitch set off the car bomb in the Jilam area south of Samarra, according to Majeed Ali, the head of the Sahwa militia force in the city, and a police officer.
Jilam, a mostly rural farming area just south of the mostly-Sunni city of Samarra, has long been an insurgent stronghold.
The 08:00 (05:00 GMT) blast went off within a compound in the area, Ali and the police officer said.
Violence has surged markedly higher in recent months, with more than 1 000 people killed in January alone according to government data.
Attacks have largely been concentrated in Baghdad and Sunni Arab parts of Iraq's north and west, including the Samarra region.
Analysts and diplomats have urged Iraq's Shi'ite-led government to reach out to the disaffected Sunni minority to undermine support for militants, but Prime Minister Nuri al-Maliki has taken a hard line ahead of April elections.