DETECTIVES are continuing to probe two major fires at recycling plants – but admit they face an uphill battle in their search to find what triggered the blazes.

More than 70 firefighters battled 40ft flames at Young's Recycling, at the Graythorp Industrial Estate, Hartlepool.

The site had to be dowsed down for two weeks by firefighters and part of the building demolished due to the size of the blaze.

Residents in nearby homes were told to stay indoors and shut their windows as thick smoke billowed from the estate.

The A Jones waste recycling plant at the Sandgate Industrial Estate, in Mainsforth Terrace, Hartlepool, fell victim to a fire just a week later.

Police have been investigating both incidents, but say they have been hindered by the lack of evidence because of the scale of destruction at the sites.

A spokeswoman for Cleveland Police said: "Inquiries are continuing and they are both ongoing incidents. Sadly, there are no positive lines of inquiry.

"Due to the fires most of the possible forensic evidence has been destroyed, which has severely hampered inquiries."

Police say they cannot rule out the possibility of the two fires being linked, but due to the damage they can not still not say for certain whether the fires were started deliberately or not.

Fire chiefs say their attendances at both incidents left them stretched with officers also having to deal with a string of smaller nuisance fires started by arsonists.

The fire officers also visited adjoining businesses on the Sandgate Industrial Estate to give advice, as they did with companies at Graythorp.

The blazes came just days after the Mail reported how arsonists cost town taxpayers £2.8m after starting more than 700 fires in 12 months.

Anyone with information on either fire can contact Hartlepool CID on (01642) 302126 or Crimestoppers on 0800 555111.