The exporting of oil at Khour al-Zubair port, located west of Basra, has been suspended after protesters closed the roads leading to the port.
On Monday, protesters closed the entrance of the port and prevented the employees and trucks from entering, which resulted in retreat of the exporting process by 50 percent.
The port was previously closed from October 29 to November 9.
Over 300 persons were killed since mass protests began in Baghdad and the southern provinces of Iraq in early October. The protests are the biggest since the downfall of Saddam Hussein in 2003.
Protesters have been calling for the ouster of the government over corruption.