A former Mexican president, Luis Echeverria, has given evidence to a congressional commission investigating the killing of student protestors in Mexico City by security forces in 1968.

Mr Echeverria was interior minister at the time of the Tlatelolco Square massacre, when troops backed by tanks opened fire on demonstrators just days before the opening of the Mexico City Olympic Games.

After the hearing, Mr Echeverria said that the army had been ordered to open fire, but he had not himself given the order.

Fewer than forty people were officially reported to have been killed, but other reports say the death toll was about three-hundred.

From the newsroom of the BBC World Service