Thailand has detained three Thai Muslims they suspect were planning to attack western embassies and tourist spots in the country.
Western embassies in Bangkok were allegedly targeted
The men were detained in southern Narathiwat province bordering Malaysia and have been linked with regional terrorism network Jemaah Islamiah (JI).
One report linked their arrests with that of a Singaporean man arrested last month in Bangkok and now in detention in Singapore.
Australia and New Zealand last month advised against non-essential travel to Thailand, warning that the country was at risk of attack by Islamic militants.
Thai Prime Minister Thaksin Shinawatra admitted to the presence of JI members in the country, but said they were not active.
According to Thai police, the three men arrested on Tuesday were planning to carry out attacks in the tourist attractions of Pattaya and Phuket, in addition to foreign embassies in the capital Bangkok.
A police official told Reuters news agency that the three men - a religious teacher, his son, and a medical doctor - were part of a cell of at least five, and that the others were being searched for.
The Singapore Government said that the man it was holding - named as Arifin bin Ali, alias John Wong Ah Hung - was detained following a tip from the island state's intelligence agency.
A government statement said the man's targets were five foreign embassies in Bangkok, including the Singapore mission.
The issue of regional terrorism is expected to be high on the agenda of a meeting of the Association of South East Asian Nations (Asean) to be attended by US Secretary of State Colin Powell next week.