COLOMBO, April 22 (Xinhua) -- The Sri Lankan government imposed a new dusk-to-dawn curfew, one day after a wave of explosions killed 290 people and wounded over 500 across the island nation, the police said on Monday.

The nationwide curfew was declared from 8 p.m. Monday to 4 a.m. local time Tuesday, according to the police.

Security has been beefed up after explosions rocked two churches in the capital Colombo and another one in the eastern town of Batticaloa. Blasts were also reported at four hotels and a housing complex in Colombo.

Police spokesperson SP Ruwan Gunasekara said 24 suspects had been arrested so far as investigations were ongoing to nab more suspects.

An islandwide curfew imposed after the Easter Sunday attacks was lifted on Monday morning.

However schools would remain closed on Monday and Tuesday.