International airlines have suspended flights to Yemen’s main airport for 24 hours due to weeks of clashes between rebels and Islamist fighters near the capital, authorities said.

“Arab and foreign airlines have decided to suspend their flights to Sanaa for 24 hours because of developments in the capital,” the Civil Aviation Authority said overnight.

The measure could be extended or reconsidered depending on the security situation, it said in a statement carried by the official Saba news agency.

The move follows fighting between Shiite rebels, known as Huthis or Ansarullah, and Sunni Islamists backed by troops.

Nearly 40 people were killed in violence just outside the capital on Thursday.

The clashes came as UN envoy Jamal Benomar held talks in the rebel stronghold of Saada to try to bring an end to Yemen’s political crisis.

The rebels, who have been camped north of Sanaa for weeks, belong to the Zaidi Shiite community, a minority in mainly Sunni Yemen but a majority in the northern highlands.

They have rejected an offer from President Abdrabuh Mansur Hadi to name a new prime minister and reduce a controversial fuel price rise, two of their core demands.

Analysts say they are trying to establish themselves as the main political force in the region.