LONDON — A woman with an 8-month-old child and her husband appeared in court yesterday among 11 people charged in connection with a plot to blow up trans-Atlantic airliners.

Cossar Ali, 24, of Walthamstow, east London, appeared accused of failing to disclose information about her husband that could have helped prevent an act of terrorism.

Ahmed Abdullah Ali, also known as Abdullah Ali Ahmed Khan, 25, from Walthamstow, was one of eight men accused of conspiracy to murder and of intending to commit acts of terrorism.

They are said to have planned to smuggle the component parts of improvised explosive devices onto aircraft and later assemble and detonate them on board.

If found guilty, they face life in prison.

It is alleged that the liquid bombs were made from hydrogen peroxide with electrical components to detonate them.

A 17-year-old youth, who cannot be named for legal reasons, is accused of possessing a book on bomb-making and a box, which was found under his wife’s bed, containing a number of wills and suicide videos.

Mrs. Ali showed little emotion as her barrister, David Gottlieb, indicated that she would plead not guilty and applied for bail, which was denied.

An order was made by District Judge Timothy Workman that banned reporting of the defendants’ addresses to protect their families from intimidation.

Up to 100 people packed the small courtroom at Horseferry Road magistrates’ court for the hearings, including several journalists from America.

All seats in the public gallery were occupied, leaving many onlookers sitting on the floor and even in the witness box.

The bearded men appeared wearing white sweatshirts and grey jogging bottoms at the court, which is a short distance across London from Paddington Green Police Station, where they had been questioned for more than a week.

With short hair and a neatly clipped beard, Tanvir Hussain, 25, who said he was of no fixed abode, was the first to appear, surrounded by five dock officers.

Alongside him were Assad Ali Sarwar, 26, from High Wycombe, Bucks, and Adam Khatib, 19, from Walthamstow, who had a thin, wispy beard and gave an “okay” sign to the public gallery as he was led away.

Abdullah Ali Khan, who confirmed his name and date of birth for the court, followed them.

Alongside him were Umar Islam, 28, from West Ham, east London, who had changed his name from Brian Young, and Arafat Waheed Khan, 25, from Walthamstow. Ibrahim Savant, 25, from Stoke Newington, north London, and Waheed Zaman, 22, from Walthamstow, were the last to appear charged with the main conspiracy.

Lawyers speaking on behalf of the eight men said they contested assertions made on behalf of the prosecution by the head of the antiterrorism division of the Crown Prosecution Service, Susan Hemming.

Judge Workman ordered all of the men to be remanded in custody before an appearance at the Old Bailey in September.

Mehran Hussain, 23, from Chingford, Essex, also appeared accused of withholding information about his brother, Nabeel, who remains in custody.

His lawyer, along with those for Mrs. Ali and the 17-year-old, indicated that they would plead not guilty and were remanded in custody for a week before a further hearing.