Hauliers are calling on the Government to cut fuel duty urgently
Hauliers angry about the cost of fuel are protesting at two oil refineries in west Wales - and say they are prepared to stay there for the rest of the week.
Around 65 lorries are at Chevron in Pembroke Dock and Murco in Milford Haven, where they are asking oil tanker drivers not to leave the sites.
It is understood only one tanker has left the site since 0400 BST on Monday.
The protesters are calling on the Government to cut fuel duty urgently.
Haulier Mike Greene said demonstrators were prepared to carry out the protests "for as long as it takes."
He said: "Something has to be done."
The hauliers took part in a go-slow protest on Sunday evening, leaving Cross Hands in Carmarthenshire at 1900 BST
They arrived in Pembrokeshire at 2100 BST and have been at the refineries overnight.
So far, around 65 lorries are at the depots but Mr Greene said he was expecting more vehicles to join their protest as news spread.
He said: "This is just the start. We will stay here for as long as it takes. We were here for a week in 2000 [during a previous protest]. This time we might be longer. Everyone's prepared to do it."
He said there was lots of support as the hauliers took part in the go-slow with people waving from bridges.
A spokeswoman for Chevron said there had been no disruption to fuel supply.
"Chevron can confirm that approximately 30 fuel tax protesters are present at its Pembroke Refinery, she said.
"The protesters arrived at approximately 9.30pm on Sunday evening, but are not blocking the entrance to the refinery. The protest is peaceful and there has been no disruption to supply."