TEHRAN: An explosion rocked a key oil refinery in Iran’s southwestern city of Abadan overnight, state media said Friday, reporting no casualties.

The explosion was caused by the “bursting of one of the furnaces of the sulphur production unit of Abadan refinery”, state news agency IRNA said.

The blast “did not cause any casualties”, it added, noting that production at the refinery was continuing as usual.

The news agency described the plant as “the oldest refinery complex and one of the biggest in Iran”, adding that it “supplies 25 percent of the country’s fuel needs”.

Industrial accidents are common in Iran, with a series of similar incidents occurring last year, including a large fire at an oil refinery in southern Tehran.

Some in the Islamic republic blame the incidents on Israel, while others consider US sanctions – which almost completely isolate Iran from the rest of the world, complicating the maintenance of industrial facilities – as a more likely cause.

A cyber attack last October halted all fuel distribution stations nationwide, prompting sharp responses from Iranian officials, who accused the United States and Israel of being behind the attack.

The city of Abadan in Khuzestan province was also the site of one the deadliest disasters in the country in years.

A 10-storey building that was under construction in the city collapsed on May 23, leading to the deaths of 43 people and sparking a series of demonstrations across the country accusing the authorities of corruption and incompetence.