Santiago: Nearly 100 former Chilean soldiers and secret police from Augusto Pinochet's dictatorship were ordered detained on Monday.

Investigating judge Victor Montiglio ordered the detentions in a probe into the kidnapping and killing of 42 people in the 1973-1990 dictatorship.

It is the biggest single mass arrest for abuses during the period, judicial sources said.

Among those being probed is the former head of the infamous Dina intelligence service Manuel Contreras, already jailed for other abuses.

Many of the newly detained will be held in military compounds.

The Dina service ran torture centres where hundreds of people were either killed or kidnapped without a trace.