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. Last Updated: 07/27/2016

Police: Bombers Made Practice Run in London

LONDON -- Less than two weeks before they attacked London on July 7, three of the four bombers traveled to the city for what appears to have been a practice run, the police said Tuesday.

The new information came a day after Osama bin Laden's chief lieutenant, Ayman al-Zawahiri, appeared in a videotaped message claiming that al-Qaida was responsible for the attacks. Three weeks ago, Zawahiri was shown in a different tape praising the bombings. British and European anti-terrorism officials said that they were investigating the claims but had reached no conclusions about who was responsible.

"Al-Qaida is quite content to take responsibility for any number of terrorist attacks, regardless of the nature or extent of their role, including whether they had an inspirational role or a more significant one," said a U.S. counterterrorism official, who requested anonymity because he was discussing sensitive intelligence assessments.

A U.S. intelligence official noted that the tape of Zawahiri had been released by the Sahab media office, the usual outlet for such statements. Recent tapes have included English-language subtitles, indicating they were aimed at Americans and Britons.

Whatever group was the mastermind, officials are coming to understand more clearly the events leading to the attacks, which killed 56 people, including the four bombers, and injured 700. On Tuesday, they released closed-circuit television images showing that three of the bombers -- Mohammad Sidique Khan, Shehzad Tanweer and Germaine Lindsay -- met at Luton station at 8:10 a.m. on June 28 before traveling to King's Cross station in London.

They arrived at King's Cross at 8:55 a.m., were captured again on camera at the Baker Street station at noon and were seen on yet more cameras leaving King's Cross at 12:50 p.m. and arriving back in Luton at 1:40 p.m.

"The implication is that they were possibly conducting reconnaissance on that day," Deputy Assistant Commissioner Peter Clarke, head of Scotland Yard's anti-terrorism unit, told reporters. "We know that is part of a terrorist's methodology: to check timings, layout and security precautions."