Five men facing terrorism charges after a series of raids in the South East have been remanded in custody by Belmarsh magistrates.
Ammonium nitrate fertiliser was seized from a self storage unit
The men will appear at the Old Bailey for a preliminary hearing on 15 April. They were charged on Thursday after being held and questioned for 10 days.
Four of the five were charged with conspiracy to cause an explosion.
Two of them, along with the fifth man, were also charged with possession of 600kg of ammonium nitrate fertiliser.
Eight men were arrested in the operation across London and the South East on 30 March.
A ninth, a 27-year-old, was arrested two days later in Crawley, West Sussex, and later released.
One of the group, a 17-year-old man, has already been accused of conspiracy to cause explosions, and will return to Bow Street Magistrates' Court on 14 April.
The remaining two men, a 21-year-old and a 19-year-old, were released on Thursday after questioning at Paddington Green Station.
The four charged with conspiracy to cause an explosion likely to endanger life or injure property are:
Anthony Garcia, 21, of Ilford, Essex
Jawad Akbar, 20, from Crawley, West Sussex
Omar Khyam, 22, of Crawley and
Waheed Mahmoud, 32, also from Crawley.
The men are alleged to have "unlawfully and maliciously" conspired with the 17-year-old to cause an explosion
between 1 October 2003 and 31 March this year.
Mr Garcia, Mr Khyam and the fifth man, Nabeel Hussain, 18, from Horley, Surrey - were also charged under the 2000 Terrorism Act with possession of an article for purposes of terrorism.
They were charged with possession of 600kg of ammonium nitrate fertiliser which it is alleged they kept at a storage unit in Hanwell, west London, for a "purpose connected with the commission, preparation or instigation of an act of terrorism".