Iraq has resumed oil exports via an undamaged pipeline to Turkey after they were cut by an explosion in the country's northern neighbour, officials said on Monday.

About a quarter of Iraqi oil exports are routed by pipeline to Turkey.

A high-ranking official in the Northern Oil Company told AFP that "we gradually proceeded with exporting oil to Turkey late last night (Sunday), and the export levels will reach normal levels" -- between 400 and 450,000 barrels per day (bpd) -- by midday on Monday.

The pipeline was hit by an explosion at about 9:20 pm (1820 GMT) on Friday "about 180 kilometres (110 miles) from the Iraqi-Turkish border, inside Turkey," the official said.

"The Turkish side is working on repairing the damage, but we are using a second pipeline," the official added.

Oil ministry spokesman Assem Jihad told AFP that "the Turkish side told us on Friday night there was an attack on the pipeline inside Turkey, which pushed us to stop the exports," without providing details about the incident.

He confirmed that exports resumed from Sunday night through an undamaged pipeline.

Iraq's income from oil sales jumped by nearly 60 percent in 2011 compared with the previous year on the back of higher crude prices and increased exports, according to oil ministry figures.

Oil sales account for the vast majority of Iraqi government income and around two thirds of gross domestic product. The country exported an average of 2.1 million bpd in 2011, according to Oil Minister Abdelkarim al-Luaybi.