A Thai anti-government demonstrator was shot dead and four others injured on Tuesday, an emergency official said, when unidentified gunmen fired on a Bangkok protest march, the first fatality of Thailand's political conflict in several weeks.

"We received three injured protesters at the hospital. One succumbed to a gunshot wound to the head," an official at Ramathibodi Hospital in Bangkok told Reuters.

The Erawan Medical Center, which monitors hospitals, said one person had died and four others were wounded in the incident near in northern Bangkok.

It brought the death toll to 24, with scores wounded, since protesters took to the streets in November, in a bid to force Prime Minister Yingluck Shinawatra from office.