Yemen has finished repairing a pipeline that carries crude oil to an export facility on the Red Sea after tribesmen bombed a segment of the grid, a government oil official said.

"The damage was completely repaired in the early hours of the morning," the official said.

Officials had said the bombing did not affect export operations.

The pipeline forms part of a network that brings crude from the Marib oil basin to storage tanks at the Ras Issa terminal for export.

A security official said government forces were still trying to track down the perpetrators, who preliminary investigations indicate are tribesmen not linked to militants.

No one was harmed in the bombing, which took place in a desert area in the eastern Marib province, officials have said.

Yemen is a small producer of oil with output of around 330,000 bpd and exports of about 200,000 bpd.

It has one large oil refinery at Aden with a throughput capacity of about 100,000 bpd.

In 2003, disgruntled tribesmen damaged the same pipeline in a similar bombing.

Tribesmen sometimes kidnap holidaymakers and foreigners working in Yemen to press for better schools, roads and services or the release of prisoners.

In 2002 militants bombed the French oil supertanker Limburg off Yemen's coast. In 2000, a suicide attack on the US warship Cole killed 17 US sailors. Reuters