This aerial video image made available by Sky TV shows fire engines, ambulances and emergency vehicles at the scene on the M6 toll motorway, near Weeford toll plaza in the West Midlands, England, around 116 miles (187 kilometers) north of London, after the motorway was closed following a police-led incident Thursday July 5, 2012. Armed police closed a section of the M6 highway in both directions Thursday during a police-led incident involving a bus in central England. (AP Photo/SKY TV VIA APTN) UK OUT, TV OUT

LONDON: Five men and a woman suspected of preparing terrorist attacks were arrested during early morning police raids across London yesterday, the capital’s Metropolitan Police have said.

Police said the operation was not linked to the Olympics, which start in London on July 27, but was part of a planned intelligence-led operation.

In a separate and apparently unrelated incident, armed police closed both carriageways of a motorway near Britain’s second biggest city, Birmingham, after reports of a man acting suspiciously on a coach heading for London.

A security source said the London arrests were related to international Islamist terrorism and were made at an early stage of plotting. It was not clear whether any targets were identified.

During the raids, a 29-year-old man was arrested on a street in west London while the others, aged between 18 and 30, were detained at residential addresses in east and west London.

A 24-year-old man was tasered during the operation but did not require hospital treatment. Police said the six had been arrested on suspicion of the “commission, preparation or instigation of acts of terrorism” and taken to a police station in south-east London.

British security forces are on high alert for any signs of trouble ahead of the Olympics. Seven years ago suicide bombers killed 52 people in a string of co-ordinated attacks in London. In the Birmingham incident, coach operator Megabus confirmed police were investigating an allegation against a passenger on the coach travelling from Preston in northern England to London.

All the passengers were taken off the coach and lined up on the tarmac of the M6 toll motorway just north of Birmingham.

Live helicopter television footage showed about 30 people sitting or standing inside a large rectangular police cordon.

Emergency vehicles and a bomb disposal unit were at the scene. – Reuters