Rocket hits US oil firm in Iraq's Basra

At least three people were injured on Wednesday in a rocket attack on the headquarters of US oil company giant ExxonMobil in Iraq's southern province of Basra, according to the Iraqi defence ministry.

In a statement, the ministry said a Katyusha rocket hit Zubair and Rumeila oil fields camp, operated by the Iraqi Drilling company, where Exxon Mobil and other companies have caravans housing their workers, security official Mahdi Raykan said.

There was no claim of responsibility for the attack.

The ministry said the headquarters of the US oil company was evacuated after the attack.

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

Exxon Mobil, based in Irving, Texas, did not immediately respond to a request for comment. In May, it evacuated staff from the West Qurna 1 oil field in Basra province.

As Washington-Tehran tensions escalated, there have been concerns that Iraq could once again get caught in the middle between its two top allies. 

The country hosts more than 5,000 US troops, and is home to powerful Iranian-backed militias, some of whom want those US forces to leave.

In May, the US evacuated nonessential diplomatic staff from Iraq. That came before a missile landed in Baghdad's Green Zone, near the sprawling US Embassy.

No one claimed responsibility for Wednesday's attack and Iraqi oil exports were unaffected.

Iraq's oil production capacity is about 4.7 million barrels per day (bpd), but the country currently produces between 4.4 to 4.5 million bpd under an agreement with OPEC to reduce oil production.

Iraq's oil revenue forms around 95 percent of the country's income.