Britain's High Court dealt a blow to the government Tuesday by ruling that terror suspects cannot be denied bail on the basis of secret evidence.
The court was ruling in the case of two men suspected of terrorist activities. They have been refused bail but their lawyers have not been told why.
Home Secretary Alan Johnson said he was "surprised and disappointed" by the judgment.
"We will do everything possible to keep this country safe and are taking steps accordingly in the light of this unhelpful judgment," he said.
Two High Court judges said suspects must be given an "irreducible minimum" of information about the case against them.
One of the suspects is a 23-year-old Pakistani student who was among a dozen people arrested in anti-terror raids in northwest England last year. All were released without charge, but the student is facing deportation on security grounds.
The other suspect is an Algerian national. Neither has been identified by name.
The men will not be released immediately. The government is seeking permission to appeal.
Civil liberties groups praised the ruling.
"Yet again it takes a senior judge to point out what most people already know — if the government is going to lock you up, it needs to tell you why," said Shami Chakrabarti of the rights group Liberty.