Thailand’s army has declared martial law, intensifying the turbulent nation’s deepening political crisis.

The surprise announcement in Bangkok was made before dawn on Tuesday. It was not immediately clear whether a coup d’etat was under way.

The move came after six months of anti-government demonstrations aimed at ousting the government and one day after the Southeast Asian country’s caretaker prime minister refused to step down.

The army said in a statement that it had taken the action to “keep peace and order” and soldiers entered several private television stations that are sympathetic to protesters.

A ticker on Chanel 5, an army station, however, denied the military was taking over, saying “the invocation of martial law is not a coup”.

Thailand’s army has staged at 11 successful coups since the end of absolute monarchy in 1932.