A brother and sister have appeared in court accused over an alleged plot to carry out a mass casualty attack.

Mohiussunnath Chowdhury, 28, and his sister Sneha Chowdhury, 25, both of Kirkwood Road, Luton, were arrested after their car was stopped in Luton on July 3 as part of an investigation by the Metropolitan Police’s Counter Terrorism Command.

Mr Chowdhury is charged with one count of preparing acts of terrorism, one count of possessing a document likely to be useful to a person committing or preparing an act of terrorism and one count of disseminating terrorist publications.

His sister faces two charges of failing to disclose information relating to an alleged plot to carry out a mass casualty act of terrorism, Westminster Magistrates Court heard on Tuesday.

Mr Chowdhury, who was bearded and was wearing a grey sweatshirt, white trousers and black skull cap, was remanded in custody.

He did not indicate pleas during the hearing and spoke only to confirm his name, address, date of birth and nationality as British.

His sister, who wore a decorated hijab, gave the same details and indicated not guilty pleas before she was granted bail.

District Judge Vanessa Baraitser sent the case against both for a hearing at the Old Bailey on July 29.

She also rejected a defence application to bar reporting of the defendants’ shared address.