The 17-year-old, from Dewsbury, who cannot be named for legal reasons, is accused of plotting to make bombs following a trip to Pakistan.

He is also alleged to have had a copy of the Anarchists Cookbook on his computer.

Piers Arnold, prosecuting, told City of Westminster Magistrates' Court the book had instructions for "viable" bombs

He was arrested following an anti-terror raid on his home in Ravensthorpe on September 12.

Mr Arnold said: "During the search approximately 500g of potassium nitrate were found under the defendant's bed in the room he shares with his younger brother.

"Potassium nitrate is a critical oxidising component of gunpowder. Also recovered was a file on a computer in the defendant's bedroom entitled the Anarchist's Cookbook.

"There are 17 references to potassium nitrate in the 'Improvised Explosives' section of the document which contains clear instructions on how to make explosives."

The prosecutor alleged 250g of calcium chloride was also found which features in the chapter "How to Make a Plastic Explosive". Videos including the devil's face made in smoke following the 9/11 attacks, beheadings and references to jihad were
also allegedly found at the address.

Flanked by two dock officers, the 17-year-old spoke only to confirm his details during the 30-minute hearing. There was no bail application and District Judge Timothy Workman adjourned the hearing to September 27.

The teenager is charged with possession of material for terrorism purposes under Section 57 of the Terrorism Act 2000, and with the collection or possession of information useful in the preparation of an act of terrorism, under Section 58 of the same act, between June 1, 2006 and September 17, this year.