A bomb attack on a key Yemeni oil export pipeline stopped flows of crude out of the country on Wednesday, while rival groups clashed in the capital of Sana'a.
Unknown assailants sabotaged the country's largest pipeline in central Marib province, the defense ministry said, putting it temporarily out of action. Oil is Yemen's largest export and along with gas made up 89 percent of its export revenues between 2010-2013, according to the International Monetary Fund (IMF).
No group has yet claimed responsibility for the attack, although both Islamist fighters and local tribesman have sabotaged energy infrastructure in the past. Oil and gas pipelines were attacked at least 10, and as many as 24, times last year, the US Energy Information Administration said.
Marib pipeline runs to the Ras Isa Red Sea export terminal, where crude is loaded onto tanker vessels.
Meanwhile, Shia rebels, known as Houthis, seized the headquarters of powerful al-Ahmar tribe on Wednesday. Casualty reports have varied, but medical sources told Reuters that five people had been killed in the violence, which Houthi sources said was sparked when tribal fighters refused to stop at one of their checkpoints.
Al-Ahmar is opposed to the Houthis and leads the Sunni Islamist Islah party.
The clashes are some of the worst to have taken place in Sana'a since Houthis overran the capital with little resistance from security forces in September and subsequently reached a peace deal with the political establishment stipulating the formation of a new government.
Authorities have so far made little attempt to dislodge the group, which has attempted to expand the areas under their control and clashed with local Sunni tribes and al-Qaeda in the Arabian Peninsula (AQAP), which has promised to defend Sunnis from the Houthis. Dozens have been killed in the ensuing violence.
Yemen has been in various degrees of disarray since the toppling of longtime autocrat Ali Abdullah Saleh in 2012. AQAP and other al-Qaeda-affiliated insurgents have since launched a string of deadly suicide attacks against security forces.
The US has backed President Abdrabuh Mansur Hadi's campaign against the Islamic extremists, but recent events have raised fears that Yemen could become a failed state, and the international community has been pushing for a diplomatic solution to the fighting — an effort that is so far without success. Chaos in Yemen could extend beyond its borders, particularly into Saudi Arabia, whose Sunni leaders are anxiously monitoring the situation.
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