Bahrain declared martial law on Tuesday, a day after Saudi forces arrived in the kingdom to help restore calm following weeks of unrest by anti-government protesters.

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 state, a regional oil and banking hub, with the country's security forces taking charge for the next three months, television said.



It was not clear if a curfew would be imposed or whether there would be any clampdown on media or public gathering.

On Monday, more than 1,000 Saudi troops rolled into the kingdom in a long convoy of armoured vehicles at the request of Bahrain's rulers, flashing victory signs as they crossed the causeway connecting Saudi Arabia to the island nation.

The United Arab Emirates said it also would send 500 police.

Bahrain has been gripped by its worst unrest since the 1990s after protesters took to the streets last month, inspired by uprisings that toppled the leaders of Egypt and Tunisia.

Sectarian clashes broke out in different parts of Bahrain overnight, with Sunnis and Shi'ites trading accusations in the media that they had been attacked by gangs of youths.

Violent clashes between youths wielding clubs, knives and rocks have become daily occurrences, forcing Bahrain University and many schools to close in order to avoid further trouble.- Reuters