A Thai court on Friday ordered leaders of a protest group that occupied Bangkok's airports for a week in 2008 to pay millions of dollars to the airport operators in compensation.
The self-styled People' Alliance for Democracy had sought to force out a prime minister they opposed. Criminal charges in the case have not yet gone to trial.
Thailand has seen aggressive protests by both the alliance, known as the Yellow Shirts, and the rival Red Shirt movement since a 2006 military coup. Earlier in 2008, the Yellow Shirts occupied the prime minister's office for three months.
A Civil Court document said 13 alliance leaders caused physical and commercial damage by leading demonstrators to occupy Suvarnabhumi and Don Muang airports. They were ordered to pay 522 million baht ($17.2 million) plus 7.5 percent interest to Airports of Thailand PCL, the semi-state-owned agency that operates both airports.
The agency closed the two airports, disrupting travel for thousands, for security reasons, and demonstrators defied an injunction calling for them to leave.
Panthep Wongpuapan, a spokesman for the protest group, said it would appeal the ruling.
"We did nothing wrong," he told The Associated Press. "We have clear evidence, which is a clip of the AOT governor saying that he was the one who ordered the closure of the airports. We just got onto their premises."
Peaceful Yellow Shirt protests set the stage for the 2006 coup, which the army justified by accusing ousted Prime Minister Thaksin Shinawatra of corruption and disrespect to the monarchy. When Thaksin's political allies returned to power in a December 2007 election, the Yellow Shirts initiated more aggressive protests to try to force them out, using confrontational tactics that were later adopted by Thaksin's Red Shirt supporters.
Thai court rulings forced two pro-Thaksin prime ministers out of office in 2008, and parliamentary maneuvering installed the rival Democrat Party in power.
Thaksin's allies say the courts and the Democrats are pillars of the establishment, which felt its power threatened by Thaksin's huge popularity with Thailand's poor and working classes. Court rulings have generally favored Thaksin's opponents.
The failure to bring to criminal trial the Yellow Shirts who took over the prime minister's office and the airport, while delivering quick justice to Red Shirts, has led to accusation of double standards.