BAGHDAD

Iraq’s Oil Ministry has said that it took measures to tighten security in oil facilities after a rocket attack on the headquarters of U.S. oil giant ExxonMobil in Iraq's southern province of Basra.

Condemning the attack and its perpetrators, the ministry said in a statement released late Wednesday that the attack targeted the country's "national economy and oil and gas industry."

About 20 foreign workers were evacuated from the building after at least three people were wounded early on Wednesday when a rocket struck the ExxonMobil's facilities.

A claim of responsibility has yet to be made.

Earlier in May, the company had evacuated its workers from the West Qurna 1 oilfield in Iraq due to security threats, before announcing their return at the end of the same month.

ExxonMobil is the main contractor in a long-term agreement with the Iraqi South Oil Company to develop the oilfield.

The production capacity of oil-rich Iraq is about 4.7 million barrels per day (bpd), though the country currently produces between 4.4 to 4.5 million bpd under an agreement with OPEC to reduce oil production.

Oil revenue forms around 95 percent of Baghdad's income.