UPDATED 16.33pm: SUSPECTED terrorists plotted to blow up transatlantic flights next Wednesday, according to the latest reports.

Two airline tickets for United Airlines flights from London to the US for today, August 11, and Wednesday, August 16, have been discovered by anti-terror police at the home of one of the arrested suspects, according to The Evening Standard.

The newspaper speculated that the terrorists would have had a practice run today and the plot would have been launched next Wednesday.

"The bombers were a couple of days from a test and a few days from doing it," a quoted US official said.

US airlines United, Continental and American were believed to be the targets.

The attack would have been launched in two or three waves, with as many as 12 US commercial planes destroyed above the Atlantic or over major US cities.

It's believed the bombers would have used liquid explosives hidden in drink bottles and detonators disguised in electronic gadgets.

It also emerged that at least one of the suspects left "martyrdom tapes" and that another worked at Heathrow, however the reports remain unconfirmed.

The mass terror raids across north and east London was the culmination of a massive 12 month investigation into an alleged plot by suspected British terrorists.

It was earlier reported that alarming new intelligence gathered in the past week of an 'imminent' attack triggered the raids and brought chaos to the country's airports.

A government source told The Guardian that Britain had intercepted a message from suspects in Pakistan telling the bombers to "go now".

MI5 and Scotland Yard had tracked the suspected terrorists behind the plot since the July 7 London bombings, according to the latest international media reports.

But the 24 suspects were arrested and the terror threat put at critical after the arrest of two British men in Pakistan eight to 10 days ago.

A further five Pakistanis were detained for acting as local "facilitators".

US media report that five more suspects are still on the run.

"Both the men were British nationals of Pakistani origin and were key members of the Britain-based network of militants. The arrests in Pakistan were made prior to the action in London," a Pakistani official told AFP.

Meanwhile, the US news network CNN reported that an undercover British agent infiltrated the group.

US officials revealed that a substantial amount of money had been wired from Pakistan to two of the alleged terrorists in Britain, so that they could purchase airline tickets.