AKIPRESS.COM - The chief of Thailand's coup-prone army warned Thursday his troops "may use force" to quell political violence, after three people were killed in a grenade and gun attack on protesters in Bangkok, Reuters said.

The rare official statement from General Prayut Chan-O-Cha followed a call by Thai election authorities for July polls to be postponed because of the unrest.

"I want to warn every group - especially those who use violence and war weapons against innocent civilians - to stop now because if the violence continues the military may be needed to come out... to restore peace and order," Prayut said in unusually strong comments.

He said his troops "may need to use force to resolve the situation," threatening "decisive measures" if civilians are hurt.

Unknown assailants fired two grenades into a rally camp early Thursday at the Democracy Monument - a stone's throw from the city's famed backpacker zone - followed by a burst of gunfire.

Bangkok's Erawan emergency centre said three people were killed and 23 wounded.

The latest bloodshed comes as demonstrators push for the appointment of an unelected premier in a move that has infuriated government supporters, who last week were dealt a blow after a controversial court ruling ousted Prime Minister Yingluck Shinawatra from office.

Her dismissal by the Constitutional Court has sent tensions soaring in the Southeast Asian nation, which has endured years of political turmoil pitting Yingluck's family against the kingdom's royalist establishment.

The Thai military, which has staged 18 successful or attempted coups since 1932, has been at pains to stay neutral in public during the six-month crisis despite pressure by anti-government protesters to step-in on their behalf.