BANGKOK - Thai police have stepped up security after two ethnic Uighur men from China linked to "foreign terror groups" visited a holiday island, a senior officer said on Saturday.
Fears of a militant attack in Southeast Asia have risen recently, especially after the Islamic State group claimed an attack in the Indonesian capital in January in which eight people, four of them attackers, were killed.
"At the end of March, two Uighurs came to Phuket and stayed one night and then left Thailand," police Lieutenant General Suchart Teerasawat told Reuters, referring to a tourist island on Thailand's Indian Ocean coast.
"These two have links to foreign terror groups", he said.
Suchart said police did not have information about who the Uighurs met or where they went on the island.
"We're investigating this. After staying one night the pair travelled to Malaysia and Indonesia. We understand they were eventually caught in Indonesia," he said.
Suchart said authorities were also investigating several ethnic Chechens following reports last week that some were on Phuket.
On Thursday, Thai Defence Minister Prawit Wongsuwan said he had ordered surveillance of Uighur and Chechen visitors who might have entered Thailand on fake travel documents.
Two Chinese ethnic Uighur men were arrested last year for their involvement in an Aug. 17 bombing at a Bangkok shrine that killed 20 people.
They were charged with murder and possession of explosives.
Authorities said the bomb was in retaliation for a crackdown on human smuggling gangs and not a "terrorist" attack.
The Uighur people from China's far west are a Muslim minority and Chinese authorities accuse some of being involved in militancy.
In March, Indonesian forces killed two ethnic Uighurs who linked up with an Indonesian militant on Sulawesi island. Four Uighurs were jailed in Indonesia last year after trying to join the same network.
China has said Uighurs pose an increasing threat to Indonesia.
China has long come under criticism for its treatment of Uighur Muslims.
Hundreds of people have died in recent years in unrest in the west China region of Xinjiang, where most Uighurs live.
Hundreds, perhaps thousands, of Uighurs keen to escape unrest at home have travelled via Southeast Asia to Turkey.
Some Chechens from Russia are known to have join militants in South Asia and Syria.
Suchart said intelligence showed four Chechens planned to enter Thailand last month but two of them were caught in Malaysia before they were able to travel.
"The location of the other two is not known," he said.