A blast has killed two people and wounded at least 28 in a busy shopping district in the Thai capital Bangkok, hours after supporters of Thai Prime Minister Yingluck Shinawatra promised to get tough with demonstrators paralysing parts of the city.
Sunday's blast went off near one of the few large protest sites remaining, leaving a trail of blood and sandals on the streets near the huge Central World shopping mall.
One child and a 40-year-old woman were killed and three other suffered serious head injuries, Erawan Medical Center, which monitors Bangkok hospitals, said.
"One boy who we understand was 12 years old has died from injuries sustained in the blast. Another child is undergoing an operation and a third child is still in the emergency room with us," an emergency room nurse at Ramathibodi Hospital in central Bangkok, who declined to be identified, told Reuters.
Al Jazeera's Veronica Pedrosa, reporting from Bangkok, said the officials think the reason for the blast was a grenade shot from a M79 grenade launcher.
Pedrosa said that the attack happened at a time when pro-government supporters were preparing to mobilise millions from countryside to Bangkok in support of the prime minister.
"They might easily bump into into anti-government protesters in the city," she said.
The political crisis in the country pits mostly middle-class anti-government protesters from Bangkok and the south against supporters of the prime minister from the rural north and northeast of the country. Both sides have blamed the other for instigating violence.
The violence in Bangkok has so far claimed more than a dozen people, including protesters and policemen. Hundreds have been injured in gunfire and grenade blasts linked to the demonstrations.
In an earlier attack, unidentified gunmen shot at an anti-government protest and threw explosive devices in the Khao Saming district of the eastern province of Trat, killing a five-year-old girl and wounding 41 people.
The protests are the latest chapter in a political conflict that has gripped Thailand for eight years.
Anti-government protesters have blocked Bangkok intersections for weeks with tents, tyres and sandbags, seeking to unseat Yingluck and halt the influence of Thaksin, regarded by many as the real power behind the government.
The protests are the biggest since deadly political unrest in 2010, when Thaksin's "red shirt" supporters paralysed Bangkok in an attempt to remove a government led by the Democrat Party, now the opposition.