DUBAI, United Arab Emirates (AP) - A large fire broke out Sunday in the basement of a sprawling residential complex in Saudi Arabia's oil-rich east, killing at least two people and wounding 70, civil defense officials in the kingdom said.

DUBAI, United Arab Emirates (AP) A large fire broke out Sunday in the basement of a sprawling residential complex in Saudi Arabia's oil-rich east, killing at least two people and wounding 70, civil defense officials in the kingdom said.

The early morning blaze happened in a compound in the eastern city of Khobar that is used by the state oil giant Saudi Aramco. The company said an investigation has begun into the cause of the fire.

The Interior Ministry's General Directorate of Civil Defense said the casualties involved victims of various nationalities, without elaborating. Like many companies in the Gulf, Aramco relies on migrant laborers to help bolster its workforce.

Some of those injured are in critical condition, the directorate said.

Mohammed Siddique, an engineer who lives nearby, told The Associated Press he first saw smoke coming from the complex at around 6 a.m. Emergency crews struggled to contain the blaze.

Images posted by witnesses on social media showed thick smoke pouring from the complex as helicopters hovered overhead.

"I saw at least 30 ambulances and three helicopters. The smoke was very heavy," Siddique said.

Siddique described the complex, which includes multiple buildings, as relatively new and "nicely built" with a mix of Western, Asian and Saudi residents. It is rented by Aramco and guarded by security teams affiliated with the company, he said.

Khobar was the site of a 1996 truck bombing at a dormitory for U.S. Air Force personnel that killed 19 Americans and wounded 372. The man described as the mastermind of the attack, Ahmed al-Mughassil, was arrested after a nearly two-decade manhunt, American and Saudi officials said last week. The FBI has described him as the head of the armed wing of the Saudi Hezbollah group.