BAGHDAD: An explosion rocked the building which houses the Iraqi parliament inside Baghdad's heavily fortified Green Zone on Thursday, a US military spokesman confirmed.

"There was an explosion inside the Convention Centre. The cause of the explosion is unknown at this time," Christopher Garver said in an email.

The convention centre is the name given since the US-led invasion of Iraqi in 2003 for the complex which now houses the Iraqi parliament.

"The status of any wounded or killed individuals is unknown at this time. Iraqi IZ (International Zone) security forces are responding to the blast," he added.