MADRID -- Nine additional members of Basque separatist group ETA were freed Friday following a ruling by the Spanish National Court, even though prosecutors asked to wait for a ruling from the country's highest court.

The releases follow an Oct. 21 ruling by the European Court of Human Rights, which found illegal the method by which Spain calculated the time to be served. That had resulted in ETA members staying in jail far longer than the length of their original sentences.

The nine released Friday included Domingo Troitino, who was sentenced to more than 1,100 years for one of the group's bloodiest attacks. Twenty-one people were killed in a June 1987 bombing of a Barcelona supermarket's underground garage.

The Strasbourg court had ruled that a Basque separatist sentenced to more than 3,800 years in prison for involvement in 24 killings and imprisoned since the late 1980s had been jailed too long.

At the time of Ines del Rio's conviction, prisoners could serve no longer than 30 years. The now 55-year-old also had her sentence reduced, meaning under one interpretation of the law, she should have been released in 2008.

But a Spanish policy said reductions in prison terms must be deducted from the full length of the term, which would mean she would remain in prison until 2017.

She took the policy, called the Parot doctrine, to the European court, which said it violated the European Convention of Human Rights.

The decision applies not only to del Rio but also other ETA members, and several have been freed in the days since the ruling.

ETA's campaign for a sovereign Basque state began in 1968 and left about 850 people dead. It renounced violence in 2011, but the government refuses to negotiate with it, insisting it must dissolve first.

(c)2013 Deutsche Presse-Agentur GmbH (Hamburg, Germany)