A gang of men were "indifferent to the carnage" they could have caused had their plot to blow up transatlantic airliners using liquid explosive bombs succeeded, a London court heard on Thursday.

The men, all aged in their 20s, were not far away from carrying out their plan to simultaneously bring down aircraft in mid-air as they flew from London's Heathrow airport to destinations in the United States and Canada, prosecutors said.

"They intended to cause a series of explosions on board a selected number of transatlantic aircraft," prosecutor Peter Wright told a jury on the second day of the trial being held at Woolwich Crown Court.

"These men were ... indifferent to the carnage that was likely to ensue if their plans were successful. To them the identities of their victims was a complete irrelevance," Wright said on the first day of the trial.

The men intended to smuggle on board components for homemade bombs disguised as soft drink bottles or batteries, the prosecution said as it outlined the threat. Some of those on trial would have been suicide bombers.

The suspects were arrested in August 2006, just over a year after four young British Islamists killed 52 commuters in suicide bomb attacks on London's transport system. The arrests led to a massive increase in security and brought chaos to global airports, airlines and passengers.

More than a thousand flights were cancelled in the aftermath and many countries imposed tight restrictions on carry-on baggage for several days. Limits on the carrying of liquids on planes still stand as a result of the plot.

Among data seized by police were details of flights to six North American destinations - Montreal, Toronto, San Francisco, Washington, New York and Chicago. The planes included Boeing 777s and 767s, capable of carrying between 241-285 people.

British citizens Abdullah Ahmad Ali, 27, Assad Sarwar, 27, Tanvir Hussain, 27, Mohammed Gulzar, 26, Ibrahim Savant, 27, Arafat Khan, 26, Waheed Zaman, 23, and Umar Islam, 29, are all charged with conspiracy to murder.

They are also accused of plotting "to commit an act of violence likely to endanger the safety of an aircraft", namely an explosion on board a plane.

The men - one from north London, another from High Wycombe, west of London, and the rest from east London - deny the charges. They sat in the dock, all dressed smartly and flanked by security guards.