British newspapers have reported that 12 terrorism suspects arrested on Tuesday included a senior al-Qaeda figure planning to attack Heathrow airport.
The Times, the Daily Telegraph, the Daily Mailand the Suneach ran versions of the story, citing unnamed Pakistani officials who said plans to attack Heathrow airport were found on the computer of Mr Mohammad Naeem Noor Khan, arrested last month in Lahore.
All four reports also mentioned an alleged senior al -Qaeda operative in Britain named Mr Abu Musa al-Hindi or Abu Eisa al-Hindi. Three of the four papers said Mr Hindi had the task of carrying out the Heathrow attack.
Police would not comment on the identities of the 12 men they were holding. A 13th was freed without charge.
Most of the reports linked the arrests in London with recent arrests in Pakistan and this week's security alert in New York and Washington.
If true, that could help persuade sceptics in the United States who have questioned the justification for this week's alert, which led to some of the most disruptive security measures since the September 11th, 2001, attacks.
US officials have said Mr Khan's computers included scouting reports about financial buildings in the United States that might have been targets, prompting the tough security measures in New York and Washington this week.
US officials have since admitted most of the information on the seized computers was several years old. But they say the timing of the security alert was justified because other intelligence pointed to an increased likelihood of attacks during the US presidential election campaign season.