Al-Qa'ida suspects face terrorism charges amid warnings of new attacks

Three suspected supporters of al-Qa'ida are to appear in court today on terrorism charges amid a series of intelligence warnings about the threat of an attack – possibly with poisonous gas – on Britain by Islamist extremists.

Reports that the three north African detainees had been preparing to release deadly chemicals on the London Underground were dismissed by security sources.

The three unemployed men, who were arrested in London allegedly with forged documents, are charged over the possession of articles for the preparation, instigation and commission of terrorist acts. They were seized on 9 November during a series of raids by Scotland Yard's anti-terrorist branch in north London. The suspects were charged under Section 57 of the Terrorism Act 2000, while three others held at the same time were later released without charge.

Rabah Chekat-Bais, 21, Rabah Kadris, in his mid 30s, and Karim Kadouri, 33, are due to appear at Bow Street magistrates' court, London, today.

The raids came after an investigation by MI5 and the Metropolitan Police. The men were suspected of supporting al-Qa'ida and an Algerian extremist group, and were believed to be considering plans for an attack. But, security sources said, it was decided to disrupt the group with early raids.

Scotland Yard denied reports that the group had plotted to kill commuters on the Underground, saying that no gas, chemicals or bomb-making equipment had been found.

Jack Straw, the Foreign Secretary, when asked whether it was safe for commuters to use the Tube, replied: "Yes, so far as I know, it's fully safe to use the Underground."

But the case has highlighted fears of an attack on the Underground by al-Qa'ida, and the Government is to place posters in Tube and railway stations advising people how to react to an act of terrorism.