Cars and pedestrians have been ordered off the streets of Baghdad after the Iraqi government announced a one-day curfew.

No reason has been given for the curfew, which the prime minister's office said would last until 6am on Sunday.

US commanders have said that the first week of the Islamic fasting month of Ramadan has seen a record number of suicide bombings, and the last two weeks have seen a significant surge in violence.

Residents of the al-Adhamiya neighbourhood in the north of the city said they heard gunfire and explosions near dusk on Friday.

A security crackdown singling out insurgents, militias and sectarian death squads, begun by US and Iraqi security forces seven weeks ago, is ongoing in Baghdad.

Outside the capital sporadic violence continued around Iraq.

In the northern, mainly Kurdish city of Kirkuk, a car bomb exploded in front of a police colonel's house. At least 10 people were wounded, police sources said.

In Iskandariya, 40km south of Baghdad, a roadside bomb killed one person and wounded four.

A suicide car bomb also targeting an Iraqi army checkpoint in the northern town of Tal Afar killing two people and wounding 30, the town's mayor said.

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