Thousands of Iraqi Shias have marched through the streets of Baghdad in the latest protest against US occupation.
Thousands attended the protest
The unarmed marchers, from radical cleric Moqtada Sadr's so-called al-Mahdi army, paraded in Sadr City, a mainly Shia eastern district.
The cleric's followers have held large demonstrations since US troops closed their al-Hawza newspaper.
The protest came as gunmen shot dead a senior police officer and his driver in Mahmudiya, south of Baghdad.
Many of the marchers wore black masks and carried pictures of Moqtada Sadr.
"We are here to show the world our might, this army can be a striking force at any moment," cleric Sadiq al-Hashimi told Reuters news agency.
Police said the Baghdad rocket attack appeared to be random
"It's a time bomb that will go off at a time and place it chooses."
On Monday, Moqtada Sadr's supporters held a rally in Baghdad outside the offices of the al-Hawza paper, which US authorities had banned after accusing it of inciting violence.
Mr Sadr, a young cleric based in the holy city of Najaf, has fast risen to prominence since the US-led invasion in 2003.
Huge crowds flock to his fiery sermons calling for an end to the US occupation of Iraq. His supporters have formed the "al-Mahdi army", aiming to provide security and welfare for Shias.
On Saturday, gunmen ambushed and killed the head of police in Mahmudiya, about 20 km (12 miles) from Baghdad, as he was returning from a trip to the capital.
His driver was also reportedly killed in the shooting.
At least one person was also reported killed and several wounded after a rocket slammed into a house in the southern Dora district of Baghdad. Iraqi police said it appeared to be a random attack.
And in Baquba, north of the capital, an explosion - possibly a car bomb - close to a US military patrol wounded at least one Iraqi civilian and damaged several US vehicles.
There were reports that several US soldiers were injured but these could not be confirmed.
Baquba is located in the so-called Sunni triangle, a stronghold for insurgents fighting US-led forces in Iraq.