Strikes by some workers of Iran's oil and petrochemical industry entered its fourth day on Thursday, as nationwide antigovernment protests continued on daily basis. 

Workers at Iran's largest refineries in southern oil-rich provinces of Bushehr, Khuzestan and Hormozgan such as Abadan Refinery and the petrochemical workers in Asalouyeh, off the coast of the Persian Gulf have been on strikes since Monday.

According to reports on Thursday the workers are under pressure to break their strikes with dozens of them arrested and the rest threatened to be fired while their internet access has been cut off. 

A union for the oil workers released a statement on Thursday saying that 30 of their colleagues have been detained and security forces are rushing from nearby regions to crack down on the protesters who demand the release of their coworkers. 

In their statement, they said they will respond to the crackdown with strikes in more plants and they would not come back to work until the government’s heavy-handed clampdown on Iranians stops. 

They also called on all industrial workers to join their protest. 

A report received on Wednesday said strikers have blocked some highways linking oil and petrochemical plants in southern Iran to prevent security forces from traveling to hotspots where workers are on strike or are protesting.