Members of the Al Saadoon tribe
want an inquiry into the killing
Members of the influential Al Saadoon tribe want the assailants tracked down and called for revenge.
Last week their leader Sheikh Ali Najm al-Saadoon was shot dead in the centre of Basra by four hooded assailants. They fled after the attack.
Residents say the tribal chief had close ties with former Iraqi President Saddam Hussein's Ba'ath government.
Demonstrators included members of other local tribes. They raised banners calling for a "fair and serious investigation".
Al Saadoon tribe blames the armed wing of the Supreme Assembly of the Islamic Revolution in Iraq (SAIRI), an influential Shia group, of being behind the attack.
US detains Iraqis
On Tuesday US occupation soldiers detained about 400 Iraqis in northern Baghdad amid a campaign to crack down on a wave of attacks against American troops.
Residents of the area told Aljazeera some of the Iraqis rounded up were as young as seven years old.
They were piled into trucks and blindfolded with their hands bound behind their backs, said residents.
The US administrator for Iraq, Paul Bremer, has vowed to curb increasing attacks against occupation forces throughout the country.
On Tuesday a US soldier was killed and a second seriously wounded when rocket-propelled grenades were lobbed at them in central Baghdad.
Our correspondent in Baghdad said the occupation force’s campaign of rounding up Iraqis was systematic and ongoing throughout the country, particularly in regions which have seen attacks against it.
Suspects have also been detained in Fallujah and Al-Dholouiya, hot-beds of anti-occupation attacks. Detention periods vary from half a day to several days.
Many residents detained and questioned for the attacks are not connected to the incidents, increasing the anger of Iraqis towards their occupiers. The detained are grilled about who is behind pockets of resistance before being released.
Emotions are running high in Al-Dholouiya where Iraqis are allowed little movement, forcing many to abandon jobs. US tanks regularly patrol residential neighbourhoods.
|There has been little response to|
US calls to hand over arms
Meanwhile, US efforts to collect weapons are continuing, but with little results. Centres have been set-up for Iraqis to hand in arms, but US and Iraqi sources said there had been little response.
After US troops invaded Iraq on 9 April, the country descended into chaos and looting. Many Iraqis have taken to guarding their homes, property and businesses with arms.
Occupation troops hope an arms collection would decrease the potency of attacks against soldiers.
Two listed men held
In other developments US forces have taken into custody two more Iraqis on Washington’s list of 55-most wanted people.
A US Central Command statement issued on Tuesday said Latif Nusayyif al-Jasim al-Dulaymi, a Ba'ath party Deputy Chairman and Brigadier General Husanain al-Awadi, a regional party chairman were in US custody.
They were number 18 and 53 respectively on the Centcom “Iraqi top 55” list. The statement provided no further details.