A violent explosion rocked Aden’s oil refineries and broke out massive fire on Friday.

Al Arabiya’s correspondent, Radfan al-Dabees, said that one of the oil tanks was subject to gunfire, and a short circuit might have caused the explosion.

Dabees also pointed out mixed information around the real reason for the explosion and the fire.

An official at the refinery told AFP that “the tank that was on fire contains little amounts of oil, and the civil defense is trying to contain the fire and its expansion to other tanks that are full of oil and diesel.”

The official said that the fire that started in one of the tanks and further expanded to the pipes “is most likely due to a subversive action done by subversive people.”

A security source said that security forces have “stopped all workers from leaving and opened an investigation following initial news about the accident being an attack.”

Aden refinery’s CEO, Mohammed al-Bekri, said that civil denfese and the company’s firefighting team were able to contain the fire that started at around 7 pm local time on Friday.

He added that the process of containing the fire and preventing it from spreading took as long as an hour and a half.

The refinery had been affected by the war in 2015, and went back to operating in 2016 after more than a year.

The attack happened after Houthis attacked on Thursday al-Anad airbase, a historical airbase established by the British in Yemen, after which Martin Griffiths, the UN's envoy to Yemen, called on both parties to "exercise restraint.”