BAGHDAD (Reuters) -- Iraq's security forces urged the movement of Shi'ite cleric Moqtada al-Sadr on Wednesday to do more to ensure a truce took hold in Baghdad and offered cash rewards for militiamen who gave up their weapons.

Major-General Qassim Moussawi, spokesman for Iraqi security forces in Baghdad, said gunmen were still attacking troops in the capital despite a weekend agreement to end nearly two months of fighting that has killed hundreds of people.

Clashes broke out in Baghdad overnight and on Wednesday, police said, killing seven people and wounding 28.

The goal was to disarm the militias, Moussawi said.

Many of the Shi'ite gunmen claim loyalty to the anti-American Sadr, but his control over them is unclear.

"So far we are still at the zero stage. Nothing has been done to implement the agreement on the ground," Moussawi told a news conference.

"We expect our brothers in the Sadr bloc to help our forces implement the agreement .. Some centres will be opened to offer money to those who hand over guns willingly."

Sadr's opposition political movement in parliament and the ruling Shi'ite alliance brokered the agreement to end the fighting over the weekend.

Despite the fresh violence, residents in Sadr's eastern Baghdad stronghold of Sadr City and the U.S. military said it was calmer there on Tuesday night compared to recent weeks.

Police said gunmen fought security forces in Sadr City overnight in violence that killed five people and wounded 22 in the crowded slum. Fighting also broke out in western Baghdad's Shula district, killing two and wounding six, police said.

Heavy automatic weapon fire echoed through the streets of Shula, also a stronghold of Sadr's Mehdi Army militia, on Wednesday. Shops were closed and residents stayed indoors.

A senior political aide to Sadr has urged patience with the truce and said it might take time to take effect.

By Wisam Mohammed and Waleed Ibrahim