Fighting between Shiite rebels and Sunni tribesmen allied to Al-Qaeda has left dozens dead in central Yemen, while a suspected US drone strike killed 10 jihadists, tribal sources said Saturday. The rebels, known as Huthis, have been facing fierce resistance from Al-Qaeda fighters and tribesmen as they seek to expand their areas of control after seizing the capital Sanaa and the Red Sea port city of Hudeida.

Clashes broke out on Friday evening when Huthi fighters trying to wrest control of the mountains around the central town of Rada, in Baida province, met resistance from Sunni militias, tribal sources said.

“They were repelled each time with heavy losses,” a tribal source told AFP by telephone. “The fighting killed dozens, particularly among Huthi ranks.”

Another tribal source said Huthi rebels had been trying to bolster their presence in the province after failing to take full control of Rada.

The source said Huthi fighters were assisted by artillery units from the Yemeni army, although this could not be independently verified.

Two vehicles carrying suspected Al-Qaeda fighters near the combat zone were struck by a missile fired from an unmanned drone, leaving 10 dead, according to tribal sources.

Yemen is a key US ally in the fight against Al-Qaeda, allowing Washington to conduct a longstanding drone war against the group on its territory. At least 60 people were killed in two days of fighting last week around Rada as local tribesman and Al-Qaeda gunmen sought to halt the Huthi’s advances.

The Huthis have seized on chronic instability in Yemen since the 2012 ouster of long-serving autocratic president Ali Abdullah Saleh to take control of large parts of the country. President Abdrabuh Mansur Hadi’s Sunni-led government has failed to stop their advance, despite a UN-brokered peace deal that was supposed to see them withdraw from the capital.

The fighting has raised fears of Yemen — located next to oil kingpin Saudi Arabia and important shipping routes in the Gulf of Aden –collapsing into a failed state. The Huthis have also been accused by media watchdog Reporters Without Borders of harassing journalists in Sanaa. On Saturday, the head of independent website Newsyemen, Abdel Sattar Bajaj, said he was beaten up by rebels after being overheard by a bus driver saying they had “sown chaos” in the capital.

“They dragged me out of the bus and beat me up with their rifles,” he told AFP. “Finally they let me go but after warning they would cut off my tongue if I criticised them again.”

On Friday night armed rebels stormed the Saudi-German Hospital in Sanaa and opened fire into the air “terrorising patients and staff,” said surgeon Adnan al-Imad.

“They said they were looking for me,” he said, adding he had no clue why they wanted him.