Two people in Spain have died of the human variant of mad cow disease, in the first such fatalities since 2005, officials said Monday.

The victims were aged 40 and 51 and lived in the central Castilla-Leon region. One died in December and the other in February, said Jose Javier Castrodeza, director of public health at the regional government. Until now Spain's only fatality from Creutzfeldt-Jakob disease came in 2005 with the death of a 26-year-old woman in Madrid.

Officials appealed Monday for calm and insisted it is safe to eat beef in Spain.

The Castilla-Leon regional agriculture minister, Silvia Clemente, said the two new victims apparently contracted the disease prior to 2001 and health controls on livestock and meat production are much tighter now than they were then.

The deaths were only reported now because post-mortem testing and Spanish bureaucratic procedures for recording such fatalities take a long time, Castrodeza told a news conference.

Mad cow disease was first reported in Britain in the mid-1980s. It has been blamed on farmers adding recycled meat and bone meal from infected cows into cattle feed.

Authorities believe eating meat from infected animals can cause the human variant of the fatal brain-wasting disease. Spain has reported more than 700 cases of mad cow disease since it was first detected in this country in 2000, according to health ministry figures.