Two suicide car bombers have killed at least 24 people near the Iraqi city of Ramadi, west of Baghdad, police say.

The first exploded in a busy market in Albu Thiyab, to the east of Ramadi, killing at least 15 and injuring 30.

The other targeted a police checkpoint some 15 minutes later in the town of al Jazeera. Five police officers and five bystanders died. Ten people were hurt.

Correspondents say the attacks may be linked to an ongoing power struggle between al-Qaeda and Sunni tribes.

Frequent target

"Ten were killed in each explosion and both were from suicide car bombs," said Tariq al-Dulaimi, a senior security official in Anbar province.

The BBC's Andrew North in Baghdad says this is an area where local tribes have turned against al-Qaeda in the past six months, provoking frequent reprisal attacks by supporters of the extreme Sunni group.

The US military believes this tribal alliance is helping to reduce violence in what has long been a resistance stronghold, BBC correspondent says.

It has also been stepping up raids on al-Qaeda which it blames for most of the car bombings.

The US announced it had detained another 15 suspected members of the network on Monday. But the suicide car bombings continue - there were three reported on Sunday.

In other developments:

· The International Committee of the Red Cross appeals for an extra US $29m (UK £15m) to step up its humanitarian operation in Iraq - mainly to provide food to 600,000 destitute people who have been displaced by the violence, but also for basic water supplies and to improve medical supplies to hospitals.

· Six US troops and a journalist, who was not identified, were killed by a roadside bomb in Diyala province, the US military said. Two other US soldiers died in attacks in Baghdad.

· A prominent Sunni group, the Iraqi Islamic Party, also again accused Shia militiamen of attacks on Sunni mosques in Baghdad. It said the imam and a preacher were abducted from a mosque in the district of Bayaa.

Photo caption

US marines on patrol in the streets of Ramadi/file photo