One of six men accused of conspiring to bomb London's public transport system told a court on Tuesday that he abandoned a bid to set off a fake bomb on a subway train but later detonated the device by accident on a bus. Muktar Said Ibrahim, 29, said he had intended to set off the device - which he says was a hoax bomb not intended to hurt anyone - on the London Underground, but changed his mind because it was too crowded. "I thought I might get caught so I decided to call it off," Ibrahim told the jury of nine women and three men at London's Woolwich Crown Court. Ibrahim and five others are being tried on charges of conspiring to bomb the British capital's transport system on July 21, 2005 - two weeks after four suicide bombers killed themselves and 52 bus and subway passengers. As on July 7, the July 21, devices were carried onto three subway trains and a bus. Prosecutors say the plot failed only because, by chance, the main charge of the bombs failed to explode. Ibrahim has acknowledged constructing the knapsack bombs from a mixture of flour and hydrogen peroxide, but said they were deliberately designed not to explode. He has told the court attacks were a hoax intended to protest the occupation of Iraq. On Tuesday he said the intended targets were five subway trains - reduced to four after Asiedu got cold feet, leaving the knapsack containing his device in a park. It was found a few days later. Ibrahim said that after abandoning his own plan, he got on a bus headed toward his home in east London. "I sat down at the back of the bus and after a while I looked at the rucksack and I saw there's a wire sticking out and then I thought this might be suspicious," he said. "I put the rucksack between my legs and I was pushing the loose wire inside my ruck sack and at the same time I was trying to locate the battery. I wanted to disconnect the battery. "Accidentally it touched the loose wire and it set off the detonator."