Two packages exploded in two government buildings in the state capital of Maryland, US officials confirmed yesterday evening.
Maryland stapolice said there were no serious injuries.
The explosions occurred yesterday in the afternoon at the Jeffrey Building on Francis Street in downtown Annapolis and another at the Maryland Department of Transportation building in Hanover.
A Maryland police spokesman later said the packages produced smoke and odours when they were opened at two separate state buildings.
State officials initially said the packages exploded, but later said there were no blasts.
Spokesman Greg Shipley says mailrooms at state offices across Maryland are being quarantined until it is determined if any other packages had been sent.
A Homeland Security Department official says the department is aware of the incidents and is monitoring them.
Maryland authorities and the FBI are responding.