Saboteurs on Tuesday blew up the main pipeline linking oilfields in Yemen's eastern Marib province to an export terminal on the Red Sea, almost halting the flow of oil, officials said.
The armed group attacked the pipeline in the Wadi Abida area of Marib, the local government officials told AFP.
"Oil flow came to a near complete halt," said one official, speaking on condition of anonymity.
The same group late on Monday sabotaged Marib's power lines, leaving the province in "total darkness" and bringing the gas plant services to a halt, another official said.
The pipeline that runs 320 kilometres (200 miles) from Safer oilfields in the east to the export terminal in the western Hudaydah province frequently comes under attack in the Wadi Abida area.
The last such act of sabotage occurred on April 8.
In December, the army launched an offensive against tribesmen suspected of being behind the attacks, sparking clashes that left 17 people dead.
Signup to our newsletter and follow us on Facebook and Twitter!
Electricity Minister Saleh Sumai has repeatedly accused tribesmen loyal to former president Ali Abdullah Saleh of carrying out the attacks.
"Those who support sabotage in Marib and attack power stations are remnants of the former regime supported by Saleh," Sumai told local media in early April.
Saleh was forced out of office following an Arab Spring-style uprising that began in 2011 against his rule.
In November 2011, he signed a Gulf and UN-brokered power transfer deal by which he quit in return for immunity from prosecution for himself and his family.
Although weakened, the ex-president, whose supporters still wield much influence in Yemen, seems reluctant to retire from political life.
His opponents suspect him of trying to hamper the political transition.
Yemen, an impoverished nation, produces about 300,000 barrels of oil a day, mostly for export.
According to official figures, lost production due to pipeline attacks in the east cost the government more than $1 billion in 2012, while oil exports fell by 4.5 percent.
In July, Petroleum and Minerals Minister Hisham Abdullah said Yemen had lost more than $4 billion (3.1 billion euros) in revenue since February 2011 as a result of such attacks.