![Iranian workers make repairs to a unit at Tehran's oil refinery, Iran, Saturday, Nov. 17, 2007. Iran's president said Saturday that the Organization of Petroleum Exporting Countries is "under heavy economic and political pressures" and that the oil prices are below its real value, state-run-news agency reported. Mahmoud Ahmadinejad made his remarks prior to his trip to Bahrain and Saudi Arabia where he is due to attend the OPEC summit. (AP Photo/Vahid Salemi)](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/YXFNH4XIJY42YVKKFAYPHPX5JM.jpg?smart=true&auth=769d61d0d5ae6557127f344060f58b4ba1eb34b47c84ef44d703c96444b93856&width=400&height=225)
An oil refinery in Tehran. Industrial accidents are common in Iran. AP
An oil refinery in Tehran. Industrial accidents are common in Iran. AP
Explosion at oil refinery in south-west Iran
The plant is among the oldest and biggest refinery complexes in the country