The grenade attacks on anti-government protesters in Bangkok are believed to have been initiated by a group of people.

Deputy Chief of the Metropolitan Police, Pol Col Adul Narongsak said, they also recovered two safety pins and other fragments indicating that high-explosive RGD-5s, made in Russia or China were used during the attacks on Friday and Sunday .

Police also examined footage from security cameras in the area and questioned five witnesses as part of an official probe into the incident.

The first attacks hit the People's Democratic Reform Committee (PDRC) led by Suthep Thaugsuban on Banthat Thong Road on Friday killing one and injuring 39 others.

The second attack was on Sunday afternoon at Victory Monument where two hand grenades were thrown at demonstrators. Shots were also fired from a pistol by the suspect who fled the scene. 28 people were wounded.

On Monday, the PDRC led its demonstrators to protest at the Government Lottery Office (GLO) and Government Savings Bank (GSB).

Two gun attacks were reported at PDRC protest venues in Bangkok on Monday morning. There were no reports of any injuries.

A motorcyclist fired gunshots at guards stationed in front of the Thailand Post building at about 3am Monday. The guards used firecrackers to chase off the attacker, Post Today reported.

Shortly afterwards a similar attack occurred on guards stationed at Soi Chaeng Wattana 14.
Meanwhile, the United States government is warning its citizens of the "potential risks of travel to Thailand".

The advisory, posted on the US Department of State website, said the situation in Thailand, particularly Bangkok, is unpredictable and will likely prolong.