Iraqi officials say two suicide bombers have killed at least eight people in the holy Shi'ite city of Najaf.

Police and hospital officials said the January 1 attack at a checkpoint in Najaf, located 180 kilometers south of Baghdad, also wounded 22 people, including many police officers.

Witnesses told dpa the attackers opened fire at the checkpoint, in Najaf's district of Qadisyia, before detonating their explosive belts.

The bombing comes one day after two suicide bombers killed 28 people at a busy Baghdad market.

That attack was claimed by the extremist Sunni group Islamic State (IS), which considers Shi'a to be heretics.

No one immediately claimed responsibility for the Najaf attack.

IS militants have stepped up their attacks in recent weeks as government forces backed by U.S.-led forces are pursuing a campaign to oust IS fighters from its Mosul stronghold, a city the extremist group captured in 2014.

Based on reporting by AP, dpa, and AFP