
The protesters had committed violence in these areas, forcing it to declare the state of emergency to restore normalcy there, the government said.
The areas include districts in Nonthaburi, Samut Prakan, Pathum Thani, Nakhon Pathom and Ayutthaya.
Deputy Prime Minister Suthep Thaugsuban will be the chief enforcer of the state of emergency measures. Police and soldiers as well as civil servants will assist Suthep in the operations to restore normalcy.
After the announcement, Prime Minister Abhisit Vejjajiva went on TV to explain the reasons behind the declaration of the state of emergency and give more details about the declaration. Abhisit said the government was forced to declare the state of emergency to solve problems before the situation escalated.
"The government has to declare the state of emergency to restore normality as soon as possible," Abhisit said. He said the government would do its best to avoid any loss of life and begged for public cooperation.
Abhisit said the chief enforcer of the state of emergency would have powers to order arrests, search premises and demolish any structure, to maintain law and order.
The statement said the entire Bangkok and Nonthaburi provinces are under the state of emergency.
The following districts are under a state of emergency:
Samut Prakan province: Muang district, Bang Phli, Bang Bo, Bang Sao Thong and Phra Pradaeng
Pathum Thani: Lat Lum Kaeo, Sam Khok, Lam Lu Ka and Klong Luang, and Thanyaburi
Nakhon Pathom: Buddhamo-nthon
Ayutthaya: Lard Bua Luang, Wang Noi, Bang Pa-in and Bang Sai.