Yemen tribes
Armed tribal militants sit on the side of a road linking the Yemeni capital Sanaa with the oil-rich province of MaribReuters

Yemen's main oil export pipeline was blown up by heavily armed tribesmen on Monday, Reuters news agency reported.

The flow of crude oil was halted after the Marib province blast, in which there were no reported injuries.

Yemen's oil and gas infrastructure has often been attacked since former president Ali Abdullah Saleh was ousted in 2011, as tribes compete to win concessions from the government.

The repeated incidences of sabotage have slashed the country's export earnings and disrupted fuel supplies within the country.

The pipeline used to transport 110,000 barrels of crude oil per day (bpd,) although that number had fallen to around 70,000 bpd by December 2013.

Yemen's government is currently facing political turmoil in the capital Sanaa, where the Houthi movement has rallied thousands of ordinary Yemenis to protest over the lifting of fuel subsidies.

The protesters have demanded the resignation of the government and the reinstatement of the fuel subsidies, which were totally cut at the end of July.

Weeks of peaceful protests escalated on Sunday when Yemen's riot police used tear gas and water cannon to disperse the Houthis that were blocking the airport road.

Government warplanes also bombed armed Houthis in al-Jawf province, killing 13, Reuters reported.