About 200 Thai right-wingers launched a group on Wednesday to counter student-led protests that have taken place almost daily since mid-July to demand the departure of the government, with some activists also seeking reform of the monarchy.
While the anti-government protesters drew more than 10,000 people to the biggest demonstration in years on Sunday, counter-protests by loyalists have drawn at most a few dozen people.
The "Thai Pakdee" (Loyal Thai) group was launched at a Bangkok hotel by prominent right-wing politician Warong Dechgitvigrom, who said His Majesty the King's monarchy was under attack.
"The father of the country is being harassed ... How can Thai people stand by?" Mr Warong told Reuters.
"Our fight must be online and offline," he said, adding that the group was non-violent and had not set any dates for protests or other actions.
The return of protests to Bangkok streets has revived fears of more than a decade of colour-coded clashes between supporters of the establishment and their populist-backing opponents before a 2014 coup in which Prime Minister Prayut Chan-o-cha took power.
Many people also remember violence in 1976 when student protests were crushed after right-wing politicians accused them of being disloyal to the monarchy.
Anti-government protesters seek Gen Prayut's departure and the dissolution of parliament, a new constitution and an end to the harassment of activists. They say elections which kept Gen Prayut in power last year were manipulated. He says they were fair.
Thai Pakdee also set three demands: No dissolution of parliament, maximum legal action against anyone who seeks to topple the monarchy, no change to the constitution except via the proper channel.
