Hundreds of workers building a new power station on Teesside have staged an unofficial strike.
The dispute over pay has flared on the site at Billingham where an energy-from-waste plant is being built.
Around 250 workers, including pipe fitters and welders, walked out on Wednesday, and continued with the unofficial action on Thursday, joined by scaffolders.
The dispute is over bonus payments after work was affected by the bad weather.
A spokesman for Air Products, which will run the plant, said work was continuing despite the action, and the company was hopeful that the dispute would be resolved in the next few days.
"Foster Wheeler, the main engineering, procurement and construction management contractor at Air Products' Tees Valley renewable energy facility at Billingham, has confirmed that certain construction contractor workers have taken unofficial industrial action. The workers, mainly mechanical and piping, are expected to return to work at the site by Monday February 10.
"We believe the strike action has not been sanctioned by their trade unions nor has a ballot of the workforce been taken.
"Air Products, Foster Wheeler and the construction contractor management have held a series of talks with union representatives in recent weeks and all parties are pressing for an early resolution for the grievances submitted through the National Agreement for the Engineering Construction Industry resolution procedure.
"Work continues unaffected throughout the rest of the site. Construction of the Tees Valley Renewable Energy Facility started in 2012 and is due to enter commercial operation later this year."
Police have released more pictures of 9-year-old Joshua Easby who was last seen at 7.30am in Kays Café in Billingham. Joshua left the cafe upset. Anyone who sees Josh or has any information is asked to call the emergency number 999.
Missing 9-year-old Joshua Easby is around 3ft tall, slim build, dark short hair with a long fringe to the side. He was last seen wearing a black coat and school uniform with maroon jumper, trousers, light blue polo shirt underneath carrying a black bag with red stripe on.
Police are urgently appealing for information to trace 9-year-old Joshua Easby, who was last seen at around 7:30am in Kays Café in Billingham. Anyone who sees Josh or has any information is asked to call Cleveland Police on the emergency number 999.