Pro-government forces in Yemen have made significant gains around the city of Taiz, which has been under siege from Houthi fighters for several months.

Governor Ali al-Maamari told the AFP news agency on Friday that government troops and their allies, backed by Arab coalition air strikes, took back areas in the western and southern suburbs of the city.

They "reopened key roads that the Houthis had been blocking for nine months," said the governor, who lives in exile in Saudi Arabia.

He added that the advance should allow humanitarian and medical aid to reach about 200,000 besieged residents in Yemen's third largest city.

Dozens of people were killed on Friday as the fighting intensified between pro-government forces and rebels, security sources said.

The death toll included at least 40 Houthi rebels, 14 loyalist fighters and six civilians.

Earlier, dozens of military vehicles carried rebel fighters out of the western suburb of Taiz towards the city of Hodeida on the Red Sea, witnesses told AFP.

Taiz is located between the rebel-held capital Sanaa and the southern port city of Aden, which loyalists took back from the Houthis in July.

In November, forces loyal to President Abedrabbo Mansour Hadi announced a major offensive to try to break the city's siege.

Yemen has been torn apart by conflict for the last two years. More than 6,100 people have died - half of them civilians - since the Saudi-led coalition launched air strikes on Yemen in March 2015, according to the UN.