A large fire in the basement of a residential complex in Saudi Arabia's oil-rich east has killed at least 11 people and injured more than 200, officials said.

The blaze began early this morning in a multi-story residential compound known as Radium in the eastern city of Khobar. The complex houses workers for state oil giant Saudi Aramco, which oversees petroleum production in the Opec powerhouse.

The company said an investigation has begun into the cause of the fire, which sent thick black smoke billowing from the building.

The Interior Ministry's General Directorate of Civil Defence said victims were of various nationalities.

Some of the 219 people reported injured were in critical condition, the directorate said.

Mohammed Siddique, an engineer who lives nearby, said he first saw smoke coming from the complex at around 6am.

Emergency crews struggled for hours to contain the blaze, which authorities said was under control by mid-afternoon.

"The smoke was very heavy," Mr Siddique said. He counted at least 30 ambulances and three helicopters responding to the fire soon after it began.

Aramco said some of those hurt were treated at the scene, where an emergency command centre was set up, while others were taken to company medical facilities and local hospitals.

The Radium complex is a gated community of eight six-story buildings with a total of 486 residential units, according to Aramco's website.

Mr Siddique described the complex as relatively new and "nicely built". It is rented by Aramco and is guarded by security teams affiliated with the company, he said.

Residents affected by the blaze were being moved to alternate accommodation. Aramco promised to use "all means and available resources" to help those affected.