The Thai military has declared martial law across the kingdom but denies it has staged a coup.
Troops moved swiftly through Bangkok after the pre-dawn announcement on Tuesday, securing key sites.
The army said it had made the move to restore order following six months of anti-government protests that have left 28 people dead, hundreds wounded and dragged down the Thai economy.
Military leaders said on-going mass rallies between political rivals "could impact the country’s security and safety of the lives and properties of the public".
"The public do not need to panic but can still live their lives as normal," a statement added.
Thailand’s tourism officials said that except for the presence of soldiers on the streets, the situation remains unchanged in the city and there is no affect on transport and tourism attractions across the country.
It said there is currently no curfew in place in Bangkok or at any other tourist destination in Thailand.
"Local residents and international visitors can continue to travel within Bangkok and other destinations in the country as usual," said a spokeswoman.
"No travel restrictions have been put in place by the Foreign Office and their advice is to allow more time to travel to Bangkok airports in case of traffic disruptions."
But it warned tourists visiting the kingdom to be vigilant and avoid rally sites and demonstration marches, as well as areas where crowds may gather.
Thailand has witnessed 18 coups in the past eight decades, the last of which ousted former prime minister Thaksin Shinawatra in 2006.
