The fire service in Northern Ireland has spent £8 million on battling gorse fires this year, according to new figures.
The highest expenditure was in the Mournes area and West Tyrone, where deliberately set fires raged for several days last month.
The information was released by the minister responsible for the fire service, Edwin Poots.
The cost of battling deliberately-lit fires in the past three financial years is more than £28 million.
At one stage during the first bank holiday weekend in May, the fire service said it was receiving a call every 45 seconds, the busiest period in its history.
Land in the Mournes, Ballycastle and Gortin in County Tyrone was worst affected with hundreds of acres badly burned.
In total, the fire service attended 3,177 gorse fires in Northern Ireland between January 1 and June 12. For the last three financial years, the total number of deliberately-set fires is 10,923.
The information was obtained from a combination of Assembly answers to questions by Sinn Fein MLA Willie Clarke and DUP MLA Peter Weir.
Mr Weir said: "These figures show that the cost of dealing with deliberately-started fires is a big drain on the Fire and Rescue Service budget. That in excess of £28 million of taxpayers' money has to be spent attending to these incidents is a cause for concern.
"Over recent times we have seen an increase in the number of deliberately-started gorse fires and this is reflected in the figures, with a large increase of almost £2.5 million in the 10/11 figure from the previous year."