By 6pm this evening the mob had grown to more than 1,000 people, and traffic was reported to be backed up 10 kilometres to the north of the blockade and seven kilometres to the south of it.
At 6:40 police estimated that about 10,000 people are now trapped in the massive traffic jams, with more being added every moment. Many of these will be people trying to get to the island's airport.
Phuket Deputy Police Chief Col Peerayut Karajedi and other senior officers are on the scene trying to talk the mob into lifting their siege of the island's main highway.
The twin 17-year-olds were arrested yesterday and confessed to attacking the 25-year-old on Sunday night. They kicked her off her motorbike, breaking her leg. They then dragged her into the bushes and took turns raping her before robbing her.
Today the mob of locals said that they had blocked the island's main highway in both directions to force the police to bring the teens to re-enact the crime in front of the public. The police had already decided against a re-enactment because they were afraid the twins would be attacked by the locals.
The mob also want the twins to apologise to the parents of the victim.
In addition, the group were demanding police give a written apology to a man they arrested for the crime, before realising they had made a mistake.
With the arrival of the senior police officers on the scene, the mob, led by the rape victim's brother, have now added another demand: the removal or transfer of four unpopular police officers from the Tah Chat Chai Police Station in the north of the island.
More details as we get them.