LONDON, Sept 18: Britain’s biggest post 9/11 terrorism trial — an alleged plot to bomb targets including night clubs and shopping centres — was brought to a dramatic halt on Monday when a key defendant refused to answer questions from his own lawyer.

Omar Khyam, a British Muslim, is accused with six other men of planning the attacks.

On the start of the third day of his evidence, Khyam was asked by his lawyers about his purchase of 600kg of fertiliser and why he had stored it.

But Khyam, 24, from West Sussex, refused to answer, saying he feared he might endanger his family back in Pakistan.

Last week the former London Metropolitan University student told the Old Bailey the 9/11 attacks had made him happy.

But he said he was joking when he told friends he wanted bomb parliament during Prime Minister’s questions, the weekly session attended by the country’s most senior politicians.

Khyam denies charges that he and his co-defendants planned to set off bombs in pubs, clubs, trains, a shopping centre and synagogues using explosives made from ammonium nitrate fertiliser.

On Monday, Khyam’s lawyer Joel Bennathan asked his client: “Mr Khyam in November 2003, did you with the assistance of another or others buy and then store 600kg of fertiliser”.

Khyam responded by saying the Pakistani intelligence service had spoken with his family members in Pakistan about what had already been said about them in court.

“I think they (the intelligence service) are worried about what I may end up revealing about them. So right now my priority is the security of my family there. As much as I want to clarify matters I am going to stop.”—Reuters