LONDON - British police questioned 22 suspects Sunday in the alleged plot to bomb trans-Atlantic jetliners in mid-air, and the country's top law-and-order official warned that the risk of another attack still remained high.

Reid repeated the assertion, made before by police, that Britain has foiled four major terrorist plots since the July 7, 2005, London transit bombings, and said police were conducting about 24 anti-terrorist investigations.

While authorities in Pakistan believe they have nabbed the main players in the plot, the official said there are two or three people still at large, including Matiur Rahman, a senior figure in the al-Qaida-linked Pakistani militant group Lashkar-e-Jhangvi. Rahman's name was mentioned by one of the detainees during interrogation.