(LONDON) -- Authorities in London have arrested six possible terrorists -- subduing one with a stun-gun -- as part of a months-long international terror probe.
The investigation that prompted Thursday's arrests by armed police has so far revealed no known connection to the Olympic Games set to begin later this month, although several arrests occurred near the main Olympic venue in London, according to a police statement and intelligence sources.
Separately, as authorities searched eight homes on Thursday, police near Birmingham stopped a budget intercity bus after a passenger spotted a man pouring something into his bag, and then saw smoke coming out.
In that incident, on the M6 Motorway, armed police escorted passengers off the bus in what was intially described as a "counter-terror response." Staffordshire Police later issued a statement saying they are not treating this as a counter terrorism incident.
As armed police officers and bomb-sniffing dogs continued their investigation, passengers remained seated on the motorway, which was closed in both directions. At least 12 fire trucks were on scene supporting the police operation. The fire department appeared to have erected inflatable "Hazmat" tents.
The incident was unconnected to the arrests, authorities stated.
In the terror probe investigation, five men and one woman, ages 21 to 29, were arrested in several locations across London by officers from Scotland Yard's Counter Terrorism Command.
The arrests were the "executive action" phase of a long-running investigation led by British intelligence service MI-5.
The men and woman were all arrested on suspicion of the commission, preparation or instigation of acts of terrorism under the Terrorism Act 2000, police said. They were taken to a southeast London police station where they are in custody.
Authorities would not disclose further details of the case that might compromise their strategy for interviewing the suspects. What they seized in the searches is unknown.
Police said the arrests in London are related to a possible plot involving Islamist extremists and potential targets in the United Kingdom. The incident and arrests occurred days after two people were picked up on suspicion of plotting an attack on the London Olympic canoeing venue.
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