At least 28 girls have died and dozens have been injured after a fire tore through a crowded children's shelter in Guatemala.

The Central American country's national police department said 40 people had been injured and the Health Ministry said 14 were in serious conditions with severe burns.

Dr Carlos Soto, the director of the Roosevelt Hospital where some were being treated, said the most severe cases, all reported to be girls, had suffered life-threatening burns.

Three days of national mourning has been declared across the country.

In the past, the shelter near Guatemala City had been criticised for overcrowding, alleged abuse and escapes.

The Virgin of the Assumption Safe Home was built to house 500 children and adolescents, but at the time of the fire on Wednesday morning, there were an estimated 800 there.

It was set up to house children who were victims of abuse, homelessness, or had completed sentences at youth detention centres and had nowehere else to go.

The prosecutor for children's rights, Abner Paredes, told local media initial reports suggested the fire started when some started setting fire to mattresses in the shelter.

Jorge de Leon, the country's human rights prosecutor, said that at least 100 children had been located after escaping from the shelter and more had managed to flee.

Mr De Leon said younger children fled the shelter because they were being abused by the elder children.

"According to what they say, the bigger kids have control and they attack them constantly," Mr de Leon said.

"They also complain that food is scarce and of poor quality."

He called on authorities "to evaluate whether it is appropriate to have these different groups concentrated in one place".