Pan-Arab television network Al-Jazeera said on Thursday that one of its journalists had gone missing in the battleground Yemeni city of Taez and that it suspects he was kidnapped.

The Doha-based channel said it had not been able to contact Hamdi al-Bokari since Monday night, when the correspondent was covering fighting between loyalist and rebel forces in the central city.

It said in a statement that there were indications that the Yemeni reporter had been "kidnapped by unknown persons".

Al-Jazeera Media Network director general Mostefa Souag called for Bokari's immediate release, saying it was the kidnappers' responsibility to ensure his safety.

Other circumstances surrounding the disappearance of the journalist were unknown.

The city of Taez is under the control of Yemen's internationally recognised government, but it has been besieged by Iran-backed rebels for months.

The Huthi Shiite rebels overran Sanaa more than a year ago, forcing the government of President Abedrabbo Mansour Hadi to flee the capital for second city Aden and then abroad.

Hadi loyalists backed by a Saudi-led coalition have been fighting back, and for weeks they have been trying to retake Taez province and pave the way towards the rebel-held capital.

More than 5,800 people have been killed in Yemen since March, about half of them civilians, according to the UN.

Media watchdog Reporters Without Borders says at least five journalists were killed in Yemen last year.

On Sunday Yemeni journalist Almigdad Mojalli was killed south of Sanaa in an apparent air strike carried out by the Saudi-led coalition.