WALKERS are being urged to take extra care after fire fighters battled double the normal amount of blazes this week.

People planning to make the most of the hot weather with daytrips this weekend are asked to be on their guard after there were 300 fires in only four days, most of which were on grassland in the countryside or on the moors.

Carl Boasman, station manager of North Yorkshire Fire & Rescue Service, said: "We would ask people to please leave their portable barbecues at home and not take them into the countryside.

"Several fires in the past few days are thought to have been started by portable barbecues left unattended or disposed of while they were still hot.

"Don't light fires in or near the countryside. Sparks can fly from the fire and spread very quickly.

"Don't discard your smoking materials carelessly and make sure they are out.

"We also ask people not to leave glass bottles lying around because sunlight shining through them can cause fires."

He said the countryside fire risk index - which measures the likelihood of fire breaking out - was currently the highest it had been for several years.

He said: "In the last seven days we have attended more than double the amount of incidents we would normally go to in this period."

Several incidents have been so large that 70 fire fighters have been needed to tackle the blaze and up to 50 per cent of the county's resources have been needed to tackle grass fires at anyone time.

"The risk of fire is extreme at the moment, " Mr Boasman said.

"For us to be able to deal with our normal workload we really need to keep our resources where they are most needed - which is in populated areas."

He said contingency plans had been put in place in York so that as soon as one fire engine was committed to a job it would be replaced by another - but it could take up to 30 minutes to get there on the county's roads.

Fire crews were still keeping a 24-hour presence on part of the North York Moors after a huge fire broke out on Saturday.

The main blaze, on 70 hectares of land near Ruswarp, has been extinguished, but hot spots have been reigniting due to the hot and dry conditions and a change in the wind direction was fanning the smouldering embers.