Two roadside bombs killed three people and injured 22 near a security checkpoint manned by members of the government-backed Sahwa militia in northern Iraq on Wednesday, police said.
The blasts, which occurred in the town of Shirqat, 300 km (190 miles) north of Baghdad, happened in quick succession, killing two Sahwa members and a civilian, a police source said.
The three were killed by the first explosion while the second caused further injuries after a gathering crowd ignored calls by police to disperse.
"We were using loud speakers, asking people to disperse but the people did not move. That's why there were many wounded people," the source said on condition of anonymity.
The Sahwa, recruited mainly from the Sunni Arab minority and including former insurgents who turned against al Qaeda, are credited with helping turn the tide of the sectarian warfare that gripped Iraq in 2006-07.
Earlier on Wednesday gunmen killed a construction worker near his house in Mosul, 390 km (240 miles) north of Baghdad while a roadside bomb wounded two children in the east of the city, police said.
A roadside bomb also wounded two people in Baghdad's northern Tobchi district, an Interior Ministry source said earlier on Wednesday.
Overall violence has fallen sharply since 2006-07 but killings and bombings still occur daily, followed every few weeks by a major, devastating assault by insurgents in which dozens are killed.