The king of Bahrain Hamad bin Isa Al Khalifa has imposed a three-month state of emergency on Tuesday a day after a military intervention by Persian Gulf countries.

Bahrain TV said the king "authorised the commander of Bahrain's defence forces to take all necessary measures to protect the safety of the country and its citizens."

The royal order was due to came into force on Tuesday and would apply to all parts of the Gulf state, a regional oil and banking hub, with the country's security forces taking charge for the next three months, the Reuters agency said.

On Monday, more than 1,000 Saudi troops rolled into Bahrain in a long convoy of armoured vehicles at the request of Bahrain's Sunni rulers, after it failed to suppress “the worst unrest since the 1990s”.

On Tuesday, clashes broke out across the nation, with a doctor reporting that hundreds of protesters were injured by shotgun blasts and clubs and that one died from a bullet to the head. One of the Saudi soldiers was also shot and killed by a protester, the AP agency reported.