Eight British men planned to explode at least seven planes in mid-air using bombs disguised as soft drinks and mouthwash, the prosecution in their case told a British courtroom Thursday.

It was the first day of a trial centred around an alleged terror plot targeting at least seven airliners heading to Canada and the U.S. in 2006.

The defendants were accused of planning to conceal homemade explosives in liquids or gels, bringing them onto flights leaving London in order to detonate them above the Atlantic Ocean.

In his opening remarks, prosecutor Peter Wright said the men had planned to attack United Airlines, American Airlines and Air Canada flights leaving London's Heathrow airport in the middle of the busy summer travel season.

Details of seven flights destined for Toronto, Montreal, Chicago, New York, San Francisco and Washington were found on a memory stick recovered by police from Abdulla Ahmed Ali, one of the accused.

The defendants are: Ali, 27; Assad Sarwar, 27; Tanvir Hussain, 27; Mohammed Gulzar, 26; Ibrahim Savant, 27; Arafat Waheed Khan, 26; Waheed Zaman, 23 and Umar Islam, 29. They were arrested in August 2006 in London and Birmingham, England's second-largest city.

Wright told the court that police foiled the plot shortly before it was to be enacted. Hundreds of flights were grounded in August 2006 after police arrested the suspects, causing lengthy delays for air travellers.

The supposed plot's discovery also spurred new airline regulations that limit the amount of gels and liquids a passenger can carry.

Wright contended the group hoped to recruit up to 18 suicide bombers, and that the plot's scope was not necessarily limited to seven planes. He told the court the identified flights were scheduled to leave Heathrow within three hours of each other and each could have been carrying between 240 and 285 people.

"The plan was designed to bring about what would have been a civilian death toll on an almost unprecedented scale," Wright said.

He said the plot was intended to be a "violent and deadly statement of intent" and designed to "inflict heavy casualties on an unwitting civilian population all in the name of Islam."

The jurors in the case, which is expected to last between six and eight months, were told that the suspects planned to colour peroxide-based liquid explosives with food dye to make them look like soft drinks and mouthwash. The bombs were to be assembled and detonated mid-flight, Wright said.

Wright said the men, who all have family ties to Pakistan, had not looked into return trips.

All eight are accused of conspiracy to murder and planning an act of violence likely to endanger the safety of an aircraft.

Evidence in the case is not expected to be presented until next week at the earliest. If convicted, the men could spend the rest of their lives in prison.

With files from The Associated Press