Prime Minister Yingluck Shinawatra (Thailand)
Yingluck Shinawatra has called a snap election on February 2. REUTERS

A protester has been shot dead as the latest round of anti-government protests in the Thai capital of Bangkok spilled over into fresh violence.

The protester was killed and four others wounded when an unidentified gunman opened fire during demonstrations against Prime Minister Yingluck Shinawatra. Earlier this month Shinawatra dissolved the Thai parliament and called a snap election for 2 February.

Petphong Kamjonkitkarn, director of the Erawan Emergency Centre in Bangkok, told Reuters that one man in his thirties had been shot dead. Four people suffered gunshot wounds.

Reuters reported that several hundred protesters were camped out in tents around the walls of Shinawatra's offices, one of several rally sites around the capital. Witnesses said they were sleeping when gunfire rang out at about 3.30am (0830 GMT) on Friday. One 18-year-old protester told Reuters: "I was sleeping and then I heard several gunshots. I was surprised."

The shooting is the latest in the increasingly violent protests and comes days after two protesters were killed and scores were injured in demonstrations outside a Bangkok stadium used as a voter registration centre.

Shinawatra's Pheu Thai Party won the last election in 2011 and has a large majority in parliament. But her opponents and protesters say her brother, billionaire businessman and former Prime Minister Thaksin Shinawatra, still controls the government from his self-imposed exile. Thaksin Shinawatra was ousted in a military coup in 2006 and fled Thailand before being convicted of corruption.

The military still plays a key part in Thai politics. Deputy Prime Minister Surapong Tovichakchaikul said the government would ask the army to help provide security for candidate registrations and voting during the February election.

Speaking to reporters on Friday, Thai army chief Prayuth Chan-ocha declined to rule out military intervention, saying: "The door [to military intervention] is neither open nor closed."