Oil flow from a key Yemeni pipeline came to a halt on Thursday after tribesmen carried out a fresh attack on it, tribal sources and industry officials said.
The dawn attack by tribesmen took place in the Sarwah region between Sanaa and Marib, in the country's east, the tribal sources said.
"Oil flow has completely stopped" from the the 320-kilometre (200 miles) pipeline that links the Safer oil fields to the Red Sea port of Hodeida, the industry official said.
The pipeline has been hit repeatedly by saboteurs, with the last attack on May 24.
In December, the army launched an offensive against tribesmen suspected of being behind these attacks, sparking clashes in which 17 people were killed.
Electricity Minister Saleh Sumai has blamed loyalists of former president Ali Abdullah Saleh, who was forced to step down early last year after being in power since 1978.
Lost oil production due to pipeline attacks in the east cost the government more than $1 billion (746 million euros) in 2012, as exports fell by 4.5 percent, official figures say.