Authorities said Friday they don’t have sufficient evidence to charge two of the three Al Qaeda suspects who were arrested this week on suspicions that they were planning an attack somewhere in Europe.

Prosecutors have been unable to come up with enough proof to convince the High Court that two Chechens arrested on Wednesday in Almuradiel, near Ciudad Real, should be held in preventive custody. They have, however, asked that a third suspect, Cengiz Yalçin, a Turkish national, should be held without bail. The Interior Ministry claims that Yalcin was a supplier of explosives.

Authorities became aware of the suspects after they had entered the country from France. The Chechens were reportedly petitioning for political asylum.