By Aija Braslina
RIGA (Reuters) - Rescue workers late on Saturday stopped searching the rubble of a supermarket collapse that killed at least 54 people in a disaster that Latvia's president called "murder".
The search in the ruins of Riga's Maxima store was aborted after part of a roof which had remained intact since the Thursday disaster fell in at around 1600 GMT on Saturday.
Other parts of the ruins were also deemed unstable, making further rescue efforts too dangerous.
"After consultations with specialists we have understood that further presence of rescue workers at this scene endangers their lives," state secretary of the Interior Ministry Ilze Petersone-Godmane told a news briefing.
Prime Minister Valdis Dombrovskis announced three days of mourning from Saturday for the victims of the tragedy, in which scores of shoppers were trapped under rubble.
"This is a case which should be clearly named, that it is a murder of an enourmous amount of defenceless people," the President Andris Berzins said in a television interview.
Rescue workers freed many survivors from the ruins in the first hours after the accident, but by Saturday afternoon no survivors had been found for a day. Twenty-nine injured people were taken to hospital, 11 of whom were firefighters. Three firefighters were among the dead.
The total death toll might be higher than 54, as police said they had been notified of seven missing people who might be under the rubble.
Ambulance chief Armands Plorins said in a news briefing the chances of finding more survivors was close to zero.
The rescue service will decide on Sunday morning how to continue, as an area of around 80 square metres (860 square feet) of the 1500-square-metre store is still covered with rubble, in some places 4 metres (13 feet) deep.
Police are looking for evidence of whether failures of design or construction of the store might have caused the collapse.
Local media said workers had been building a roof garden on the supermarket, a single-storey building a 30- minute drive from the city centre.
Many people gathered near the ruins on Saturday, bringing candles and flowers.
(Editing by Andrew Roche)