BANGKOK: Thousands of supporters of ousted premier Thaksin Shinawatra massed here yesterday to show support for the embattled government, raising fears of clashes with rivals besieging the airports. This comes as grenade attacks targeting anti-government protesters injured at least 51 in the capital.

The blasts came hours before people bedecked in bright red shirts to differentiate themselves from their yellow-clad foes in the People's Alliance for Democracy (PAD), the pro-government supporters, waved national flags and wore headbands reading simply "Thaksin".

Others had "No Coup" on their red headbands, as the occupation by PAD supporters of Bangkok's two main airports over the past week has raised fears of military intervention to end the paralysing turmoil.

"We gather here to protect the democratic system, to say we don't want a coup," said pro-government leader Jatuporn Prompan.

"The group will be here until Thursday. We plan at some point to march to the Democracy Monument."

Police estimated that about 4,000 people had gathered at a plaza in the central government district near the Democracy Monument, while organisers have said they hope to bring out 10,000 people yesterday.

Their hero Thaksin was overthrown in a coup in September 2006 after PAD protests and amid allegations of corruption, and the PAD resuscitated their campaign in May this year after his allies won elections last December.

They are rallying about five kilometres away from some supporters of the anti-government PAD, who have occupied the prime minister's cabinet offices nearby since late August.

The PAD, whose supporters wear yellow shirts and headbands in what they say is a symbol of their desire to protect Thailand's revered monarchy, is locked in a stand-off with police at Bangkok's two main airports.

Thai authorities used carrot and stick tactics yesterday to end the siege at Don Muang and the larger Suvarnabhumi international airport amid fears of political violence -- and concerns that more bloodshed could spark a coup.

Police said fresh talks had started at both airports. But they later issued a new order to protesters at Don Muang, warning that they faced two years in jail if they did not disperse.

"Time is running out but we still have time to find a solution. Police will work with compromise, no force, no weapons," said Pongsapat Pongcharoen, assistant to the national police chief.