OREANDA-NEWS. Assailants blew up Yemen's main oil export pipeline, halting crude flows, local officials said, while other gunmen attacked electricity lines, causing a power outage in most of the country's northern cities.

There was no immediate claim of responsibility, but Yemeni tribesmen often attack oil pipelines and power lines. Al Qaeda-linked militants have also carried out such attacks.

The attacks coincided with an offensive by Yemeni government forces in mountainous areas of southern Yemen that led to the capture of the militants' main stronghold in that region.

The oil pipeline was bombed twice in less than 12 hours in an area between the central Maarib province and the capital Sanaa, the local officials said, an area that has suffered numerous attacks since 2011.

The pipeline carries crude from the Maarib fields in central Yemen to the Ras Isa oil terminal on the Red Sea. Before the spate of attacks began three years ago, the 270-mile (435-km) pipeline carried around 110,000 barrels per day to Ras Isa.

Separately, gunmen forced the closure of the Maarib gas-fired power plant after twice attacking its power transmission lines, the state news agency Saba reported. It was the third attack in less than 48 hours by gunmen who targeted other lines that transmit power between Maarib and Sanaa, Saba said.

Major powers have pressed Yemen to curb the Islamist insurgents and to restore order in the south to prevent threats to top oil exporter Saudi Arabia next door. They also want to reduce any risk of Yemen being used as a springboard for attacks on Western targets.