Hundreds of anti-government protesters stormed Bangkok's Suvarnabhumi international airport terminal on Tuesday night, forcing officials to halt departing flights as demonstrators fought running battles with riot police in the city.

Anti-government protesters cheer as they listen to a leader's speech during a rally on Tuesday at Bangkok's Don Muang Airport, which is being used as a temporary office for the country's prime minister. (Wason Wanichakorn/Associated Press)Members of the People's Alliance for Democracy (PAD) broke through police lines and began roaming through the sprawling $4-billion US terminal as startled tourists looked on.

The airport, a major southeast Asian hub that handles 13 million tourists each year, cancelled all departing flights as a result.

Earlier, thousands of the PAD supporters waved plastic hand-clappers, flags and portraits of King Bhumibol Adulyadej outside the airport. They also blocked the four-lane access road leading to the airport with slung razor wire.

Airport manager Serirat Prasutanon said airport authorities tried unsuccessfully to negotiate with the protesters.

"For the safety for passengers, we have to stop flights out of the airport temporarily until the situation returns to normal," he said in a statement. He said incoming flights were operating and that the provincial governor asked the army to help police.

Protesters elsewhere used trucks to block part of the highway to the airport, tying up traffic ahead of the planned Wednesday return by Prime Minister Somchai Wongsawat from Peru, where he attended a summit of Pacific Rim leaders.

"Our goal is to shut down Suvarnabhumi airport until Somchai quits," PAD spokesman Parnthep Pourpongpan said of the protest, aimed at Somchai.

The prime minister issued a statement late Tuesday saying he would find an alternative place to land, the CBC's Asia correspondent Michael McAuliffe reported.

The blockage marks the latest in a series of efforts by anti-government groups to oust the current administration.

Protesters, government supporters clash in city

Meanwhile, gunshots were reportedly fired as another large group of PAD protesters left an earlier rally on the road to the city's old Don Muang airport, a part of which was being used as a temporary office by the government.

Public broadcaster TPBS aired footage that showed at least two security guards from the PAD firing half a dozen rounds from handguns at opponents on the major road in north Bangkok.

At least 11 people were hurt, a city emergency services official said.

The PAD said its members were attacked first with planks and stones. The television footage showed members of the PAD group chasing the pro-government group, who appeared to number several dozen.

The footage showed the alliance supporters surrounding a motorcycle taxi driver and putting a knife to his throat. After the driver fled, the protesters battered several motorbikes with steel rods and set fire to another one.

The People's Alliance for Democracy opposes the current government, because it considers it to be a puppet of former prime minister Thaksin Shinawatra, who was accused of corruption and abuse of power, and was deposed in a September 2006 military coup.

Despite its name, the alliance and their sympathizers — monarchists, the military and the urban elite — complain that Western-style democracy gives too much weight to Thailand's rural majority and leads to corruption.

They have proposed a system under which most lawmakers would be appointed rather than elected.

With files from Reuters, Associated Press