A number of mortars have hit a prison in Baghdad, killing at least seven inmates, Iraqi officials say.
Rocket fire set off a large fire at the capital's only refinery
About 20 others, including several policemen, were injured in the incident, reports say.
The prison is close to the main buildings of the interior ministry, and it is not known if it was specifically targeted for attack.
Also on Monday, a serious fire broke out at a storage tank in the Doura oil refinery on the outskirts of Baghdad.
Initial reports said the fire was a result of rocket or mortar fire.
But a later statement from the US military said the fire resulted from an industrial accident.
The Americans said a pipe had exploded, and it was not yet clear how many casualties there were.
Assim Jihad, the Iraqi oil ministry spokesman, said the area was sealed off and the fire was under control
Firefighters were trying to put out the blaze many hours after it broke out.
The Doura oil refinery is the only one in Baghdad. Since the fall of Saddam Hussein many of its employees have been targeted by insurgents.