Deputy police chief Srivara Ransibrahmanakul told reporters that it was likely that those aiming to attack the capital might be the same group that carried out a series of bombings in central and southern Thailand in August.
Srivara said security had been increased in Bangkok and its vicinity, particularly tourist attractions and embassies. Intelligence suggested the attacks were planned for the period between October 25 and October 30.
In August, 11 bombings targeting tourist destinations and government buildings across seven provinces in one day killed four and injured more than 30.
Srivara pointed to a higher security alert in October, when the establishment of the Barisan Revolusi Nasional (BRN), an insurgent group active in the south of Thailand, is marked.
The government has denied the independence claims of the three Muslim-majority provinces in the south. The insurgency there simmered for much of the second half of the last century, flaring up again in 2004, and since then leaving thousands of casualties.
Police Lieutenant General Chayapol Chatchaidet confirmed to dpa that the number of police officers patrolling potential target areas has been increased.
Chayapol said police have coordinated with the operators of tourist attractions and shopping malls around the capital on security management, while urging the public to remain vigilant and inform the authorities if they find anything suspicious.
