Dozens of tanks have arrived in the centre of the Bahrain's capital, Manama, where demonstrators are currently demanding political reforms, world media said on Thursday.
At least four people have died and nearly 100 were injured earlier in the day in Manama as riot police suppressed demonstrators inspired by recent coups in Egypt and Tunisia.
Thousands of mainly Shiite protesters have been camped out on Manama's central square for three days demanding more political representation in the country, which is ruled by a Sunni Muslim monarchy.
Mattar's Shiite opposition Wefaq party, which has walked out of parliament, on Wednesday demanded a new constitution that would steer the country towards democracy.
MOSCOW, February 17 (RIA Novosti)
