A car bomber has struck a police checkpoint northwest of Baghdad, killing at least 5 policemen and wounding 13 people, police says.

The bomber drove a car loaded with explosives into a police checkpoint in Jarma, 30 km (20 miles) northwest of Baghdad on Saturday.

Five policemen were killed and thirteen others including six police officers and seven civilians were wounded in the bombing.

The bombing comes just a week before Iraq's provincial elections.

The January 31 provincial elections are widely held as a crucial step to secure 'peace' and 'stability' in the war-torn nation.

The country's last provincial and parliamentary elections were held four years ago.

In a Monday statement, top Iraqi cleric Ayatollah Ali al-Sistani urged people to vote in the Jan. 31 provincial elections.

Al-Sistani asked voters to "screen and check who's qualified" and to choose candidates who possess the "qualifications, integrity and loyalty to serve the people."

MSH/DT