A Spanish judge on Sunday jailed two Chechens suspected of belonging to Al-Qaeda and possessing bomb-making material, a judicial source said.
A Turk who was arrested at the same time on August 1 had already been jailed on Friday after Spain's interior minister said investigators had evidence suggesting the trio were planning attacks in Europe.
The Chechen pair were arrested on a bus heading for the French border and the Turk in a flat in the southern province of Andalucia, where police also discovered the explosives.
The judge jailed a Turk accused of being an Al-Qaeda operative for "possession of explosive substances and devices with terrorist aims", but did not agree with prosecutors that the man belonged to a terrorist group, the source said.
After the men's arrest Wednesday, Interior Minister Jorge Fernandez Diaz said investigators had a "clear indication" that the men had been planning an attack in Spain or elsewhere in Europe.
He called the suspects "extremely dangerous people", including one who was "a very important operative in Al-Qaeda's international structure".