Iraqi officials say a blast near a Shi'ite shrine in the holy city Karbala has killed at least 55 people. Locals say the bomb detonated as many worshippers gathered for evening prayers at the Imam Abbas shrine. VOA's Barry Newhouse reports from northern Iraq. 

Firefighters hose down burning vehicles following an explosion in a crowded commercial area near the Imam Hussein shrine in Karbala, Iraq 28 Apr 2007

Violence elsewhere in Iraq killed at least 10 people on Saturday, including three children in a mortar attack in western Baghdad.

Earlier, in a statement from Baghdad, the U.S. military said that coalition forces conducting raids on suspected al-Qaida in Iraq cells detained 17 suspected terrorists in cities north and east of Baghdad and in the northern city of Mosul. The suspects are accused of murders, kidnappings, weapons smuggling and organizing car bombings. Officials said two of those detained are suspected of having ties to the bombing of Baghdad's landmark Sarafiyah bridge earlier this month. None of the suspects was identified, although officials said one served as an intelligence officer for al-Qaida.

In Sadr City, a Shi'ite neighborhood of Baghdad, U.S. and Iraqi forces detained four suspected insurgents in an early morning raid.

The U.S. military also announced Saturday that an operation earlier this week uncovered more weapons with links to Iran.

U.S. military spokesman Lieutenant Colonel Christopher Garver said Iraqi and  U.S. forces found a cache of rockets and mortars.

"These weapons are distinctively marked so that we know they are coming from Iran," he said.  "We know the smuggling routes and the Iraqi border security teams are working to close down those smuggling routes where you see the smuggling coming in from the south of Iraq and into Baghdad up from the South."

For months U.S. officials have accused Iran of training and supplying insurgents in Iraq with weapons and high-powered explosives. Last week, the top U.S. commander in Iraq, General David Petraeus, said an Iraqi insurgent group, known as the Khazali Network, has close ties with Iran's elite Quds Force military unit and was involved in killing five U.S. soldiers near Karbala in January.