Baghdad - US and Iraqi forces Sunday imposed a siege on central Baghdad's al-Fadl neighbourhood, blocking roads leading to it, a day after clashes erupted with members of a Sunni militia group.

Iraqi police and army forces were deployed in the neighbourhood and asked inhabitants to hand over their weapons, witnesses told the German Press Agency dpa.

Armed clashes erupted Saturday evening as American and Iraqi troops arrested a key leader of the Awakening Councils, Adel al- Mashhadani, and his aide on "terrorism charges," including murder and displacement.

The Awakening Councils, or Sahwa fighters, are some 99,000 Sunni tribe members, who, repulsed by al-Qaeda's killings of civilians, allied themselves with US forces. They turned on al-Qaeda militants and succeeded in expelling a large number of them over the past few years.

At least two Iraqis were killed and 15 injured during the clashes, al-Arabiya news channel reported.

Qassem Ata, spokesman for the Iraqi security forces in Baghdad denied earlier press reports that the group's fighters are detaining a number of Iraqi security officers. He also denied any killings among security forces.

"Al-Mashhadani is only a suspect. He will stand trial and can present evidence of his innocence."

In recent months the Awakening Council Sahwa fighters, who largely ended the violence in Sunni provinces, have been complaining that they are disregarded and mistreated by the Iraqi leadership.

The group has also blamed Iraqi Prime Minister Nuri al-Maliki for failing to fulfil his promise to integrate 20 per cent of the Awakening Councils into the Iraqi security forces.

Al-Madhhadani himself has recently warned fighters could turn against the government.

The tribal groups are supported by US money and training, receiving 300 dollars per month per person.

Since the beginning of October, the Iraqi government enjoys full administrative control of some 54,000 members in and around Baghdad and has became responsible for providing their salary.

"The Iraqi government has paid the March paycheques for the Sahwa fighters. We have never and will never deny the major role which the Awakning Councils played in securing stability in different parts of Iraq," Ata said. dpa