Suspected insurgents burned Thai flags and raised Malaysian flags in their place in a coordinated operation Friday across Thailand's Muslim-dominated south that also saw the militants plant bombs that wounded six soldiers, officials said.

The unrest came on the anniversary of the 1989 founding of an umbrella separatist group that combined four Thai separatist movements, as well as the anniversary of neighboring Malaysia's independence from British rule.

The insurgents are mainly ethnic Malays, but it's not clear why they would raise Malaysian flags. Analysts say the militants want a separate state but have never indicated they want to be part of Malaysia.

More than 5,000 people have been killed in Buddhist-dominated Thailand's southernmost, Muslim-majority provinces since an Islamic insurgency flared in 2004. Improvised bombings and shootings against security forces and civilians have been common insurgent tactics, but flag burnings are rare. The last time Malaysian flags were raised was in 2009 during a visit to southern Thailand by Malaysian Prime Minister Najib Razak, said Sunai Phasuk, a senior researcher for New York-based Human Rights Watch.

Sunai said it was a mystery why insurgents would raise Malaysian flags. "There is no convincing reason," he said.

Thailand accuses Malaysia of harboring Thai insurgent leaders as well as militants suspected of carrying out attacks. Malaysia denies the charges.

Col. Pramote Prom-in, deputy spokesman of the Thai government's regional security agency, told reporters the insurgents were trying to damage relations between Thailand and Malaysia. But he said that would not have any impact, since "Thailand and Malaysia have had a good relationship all along."

In Friday's violence, police said Thai flags were burned and Malaysian flags were displayed prominently along roads and on electricity poles, trees and pedestrian bridges in the southernmost provinces of Yala, Pattani and Narathiwat, as well as predominantly Buddhist Songkhla province.

Pramote said the six wounded soldiers were injured in several separate bomb attacks in Narathiwat.

One of the troops was helping his unit seal off an area around a mobile phone network tower after they found a Malaysian flag on it, said police Col. Patta Madawa.

Authorities found suspicious items, including boxes wrapped in black tape and empty gas canisters, at 102 spots across the four provinces on Friday morning, according to the Internal Security Operations Command, the government's regional security agency. Several of the items were bombs, while most were apparently fake bombs and posed no real danger, the agency said.

Sunai said the insurgents aimed to show their wide reach in the operation.

"They want to show they can infiltrate every province of the south," he said. "Even if each operation was relatively small in size, it shows their coverage is wide."


Associated Press writers Thanyarat Doksone and Todd Pitman contributed to this report from Bangkok.