Several international oil companies in Iraq, including the US ExxonMobil, were hit by a rocket on Wednesday, which left two Iraqi workers wounded, a security source said.

The incident took place in the early morning when a rocket landed on the residential section for Iraqi workers in the site which located in Burjesia area in west of Basra, the source told Xinhua on condition of anonymity.

On Tuesday, a Katyusha rocket landed on the complex of the former presidential palace in Mosul, the capital of Iraq's northern province of Nineveh, where several security headquarters are stationed in the complex, which also houses US troops tasked with training the Iraqi forces, without causing casualties.

On Monday, three Katyusha rockets landed on a military base in the evening on Camp Taji, a military base some 20 km north of the Iraqi capital Baghdad, which also houses a base of US trainers.

No group has so far claimed responsibility for the attacks.