Thai police have ordered anti-government protesters, who have laid siege to the city's airports, to disperse.
Police have also banned gatherings of more than five people and warned offenders would be jailed or fined.
Hours after a grenade blast wounded more than 50 protesters, and ahead of a big rally in the Thai capital planned by government supporters, the five-point statement did not say how police intended to enforce the emergency rules.
Flights in and out of Bangkok's Suvarnabhumi International airport and the mostly-domestic Don Muang airport have been paralysed by a siege by People's Alliance for Democracy (PAD) protesters seeking to overthrow the government.
The Department of Foreign Affairs said it has received several calls from Irish tourists stranded in the Thai capital as the airport sit-in enters its sixth day.
EU officials are expected to hold further discussions tomorrow morning about ensuring citizens stuck in Bangkok are able to return home.
Talks between the EU and Thai government have been taking place over the weekend.
A significant number of Irish people are believed to be among the thousands stranded.
The protests at Suvarnabhumi and Don Muang are the latest escalation in the PAD's ‘final battle’ to unseat a prime minister it accuses of being a front for former leader Thaksin Shinawatra.
He still has strong support among the urban and rural poor, and the pro-Thaksin Democratic Alliance Against Dictatorship (DAAD) says it will bring 100,000 supporters to central Bangkok today in a show of support for the government.
The chaos caused by the airport sit-ins has sparked rumours of a military coup, even though the army chief has said he will not seize control. The prime minister Somchai Wongsawat has rejected military calls to hold a snap election.
