It was confirmed that the blockade was the result of a major international drug bust with two arrests being made earlier this morning.

The raids were the result of investigations undertaken over the previous two years involving the supply of the chemicals used in the manufacture of crystal meth - also known as methamphetamine.

Officers from Central Scotland Police made the arrests on behalf of the US Drug Enforcement Agency.

Brian Howes, 43, from Middlesbrough, and 28-year-old Kerry Ann Shanks, from Bo'ness were arrested and will face extradition over the alleged supply of chemicals involved in production of the synthetic drug to the US, Europe and Australia.

As well as the arrests, police also swooped on a number of business addresses in Bo'ness.

It was confirmed by a police constable (earlier) positioned outside Thomson Place that a planned incident was underway which involved both police and other agencies.

No other information, at that time, was being given about the activities going on just outside the old Star Cinema.

Between 11.15 and 11.45 the road was further blocked with a tape barrier after police incident vehicle took up position outside the Coffin Block.

Given the scale of the operations it is estimated that disruption will be experienced for some time in and around Corbiehall and Bo'ness town centre.