Millions across Europe paid silent tribute to London's dead on Thursday, a week to the day since suicide attacks killed over 50 people, as police tried to track down the mastermind behind the four British bombers, Reuters reproted . In London, workers poured out of their offices to line the streets while taxis and buses came to a halt. Planes at airports switched off their engines and delayed take-offs. Hundreds gathered at King's Cross station, site of one of the blasts detonated by a group of young British Muslims of Pakistani ethnic origin who lived in northern England. Prime Minister Tony Blair, who on Wednesday said he would look urgently at new measures to tackle extremism, marked the silence in the garden of his Downing Street office, while Queen Elizabeth observed it at Buckingham Palace. Golfers at the 134th British Open championship stood quietly on the fairways and greens of the St Andrews course in Scotland. Tributes were also paid in Madrid and Bali -- both targeted by bombers from the Islamist al Qaeda network in the past -- and in cities across Europe. The Pope, on holiday in the Italian Alps, prayed for peace. Forty miles (64 km) northwest of London, police continued to search a house in the market town of Aylesbury for clues to who may have plotted the bombings -- the first suicide attacks in western Europe. They raided the house on Wednesday night but made no arrests and found no explosives. --mor 1426 Local Time 1126 GMT
