Iraq had intelligence of possible parliament attack: source

BAGHDAD (Reuters) - Iraqi authorities had intelligence that militants were planning an attack on parliament before a suicide bombing at the building, a senior government source said on Friday.

The attack on Thursday, which the U.S. military blamed on al Qaeda, killed one lawmaker and wounded two dozen other people. Some visitors said security had been tightened at the building, with sniffer dogs used earlier in the day.

"We had prior intelligence that there would be an attack on the parliament," the source told Reuters, without specifying when or how the information had been received.

He added that initial evidence showed a member of a Sunni lawmaker's security team might have played a role in the attack, the most serious breach of the heavily fortified Green Zone that houses many government offices and embassies.

"It seems initial, initial evidence points to the possibility a member of a security detail of a Sunni member of parliament might have been involved. That is based on talks with survivors and some of the wounded," the source said.

He said he was not aware of three employees from parliament's restaurant being detained. A senior Shi'ite lawmaker told reporters earlier on Friday three workers in the cafe were being held for questioning.

"Certainly this investigation will also focus on the cafe, and how this breach happened in the cafeteria," the source said.