Four men were convicted Monday of plotting to bomb London's public transport system July 21, 2005 — an attack with deliberate echoes of suicide bombings that killed 52 commuters on the network two weeks earlier.

The jury was still deliberating on two co-defendants.

The men were accused of attempting to detonate explosives-laden backpacks on three subway trains and a bus in a mirror image of the July 7, 2005, attacks. The devices — made from a volatile mix of hydrogen peroxide and flour — failed to explode, and no one was injured.

A jury unanimously found Muktar Said Ibrahim, 29; Yassin Omar, 26; and Ramzi Mohammed, 25, guilty of conspiracy to murder.

Several hours later they returned another guilty verdict on Hussain Osman, 28.

The verdicts, at the end of a six-month trial, came days after police uncovered a plot to detonate car bombs in London's entertainment district and two men rammed a flaming Jeep Cherokee into Glasgow International Airport.

Judge Adrian Fulford told the jury of nine women and three men he would accept 10-2 majority verdicts on the other two defendants, Manfo Kwaku Asiedu, 34; and Adel Yahya, 24.

All six suspects denied the charges, saying the devices were duds and their actions a protest against the Iraq war. But police and prosecutors said scientific tests proved the bombs were all viable. They do not know why they did not work.

The gang convicted Monday had bought 442 liters (117 gallons) of hydrogen peroxide — an easily available chemical commonly used for bleaching and coloring hair. At a makeshift "bomb factory" in Omar's north London apartment, they boiled the chemical to a concentration of 70 percent to increase its explosive potential.

The bombs' main explosive charge was 70 percent liquid hydrogen peroxide and 30 percent flour of the sort used to make chapatis, a type of Indian flat bread.

The explosives were packed in plastic tubs, with screws, bolts and other pieces of metal taped to the outside as shrapnel. The detonators contained triacetone triperoxide (TATP), an explosive used by the July 7 bombers.

Omar and Mohammed tried to set off their devices aboard two subway trains; a couple of hours later, Ibrahim's bomb failed aboard a double-decker bus.

Osman is accused of trying to detonate a bomb on a third subway train, while prosecutors say Asiedu lost his nerve and abandoned his device in a London park. Yahya left Britain for Ethiopia several weeks before the attacks.

During the trial, Asiedu turned on the others and claimed Ibrahim, the gang's self-proclaimed leader, had wanted the attacks "to be bigger and better" than the July 7 bombs.

The botched plot rattled a city already shaken by the July 7 attacks, as detectives launched the biggest manhunt in British history.

A day after the failed attacks, police shot dead Jean Charles de Menezes, a Brazilian electrician they mistook for one of the bombers.

Police said they were under enormous pressure to capture the men, uncertain over whether they would try again and anxious to avoid a repeat of the aftermath of the hunt for terrorists responsible for the 2004 Madrid train bombings. Then, suspects killed a police officer and themselves when they exploded booby traps as police stormed their hideout.

Most of the suspects were arrested in England a few days after the attacks. Osman fled to Italy and was detained in Rome a week later.

Giving evidence at the trial, a specialist firearms officer, identified only as PC 7512, described how he almost shot Omar dead when police tracked him down to a house in Birmingham, central England, and found him standing in a bathtub, fully clothed and wearing a backpack.

"In all honesty, I still don't know to this day how I did not shoot him," said the officer, describing how his submachine gun was trained on Omar's head.

Much of the prosecution's case was based on eyewitness testimony and closed circuit television footage from the targeted subway cars and bus.

In one of the most chilling pieces of footage, Mohammed attempts to detonate his charge with his backpack facing a mother and young child. Moments, later passengers are seen running to the other side of a carriage, while an off-duty firefighter, Angus Campbell, remonstrates with Mohammed.

Police believe the planning for the attack started after Ibrahim returned to Britain from a trip to Pakistan in March 2005. He was in the country at the same time as two of the July 7 bombers — Shezhad Tanweer and Mohammed Sidique Khan — but officials do not know if they ever met.

They believe the transit system was not the group's original target, but was chosen following the successful attacks two weeks earlier. Their original target is unknown.

Following the men's arrests, police acknowledged they had video evidence of Ibrahim at a training camp in the northern English countryside taken a year before the attacks but had failed to identify him.