Flames snake across the hillside in the Rhondda Valley as firefighters tackle a huge grassland blaze South Wales Fire Service received 265 calls about grass fires in last week Fire in Tonypandy threatened properties surrounding the mountain Eight hectares of grassland and tress were destroyed It is a yearly occurrence in the Rhondda Valleys, South Wales, but these stunning images show the devastating impact that deliberately lit grass fires have on the local environment. The fire, which took hold of a mountainside in the valleys yesterday, threatening properties between Penrhys and Tonypandy. Eight hectares of trees and grassland were destroyed by the fire, with four fire engines from surrounding towns battling for two hours to calm the snake-like flames. Snake-like: The flames spread across the valley perilously close to local homes Yearly occurrence: The grass fires happen every Easter holiday period in South Wales, with nine out of ten of them being deliberately lit The initial call at 3.26pm was one of 75 calls to the fire service about grass fires yesterday, with 265 calls being made in the last week. Each year during the Easter holidays the South Wales Fire and Rescue Service deal with hundreds of grass fires, nine out of ten of which they say are lit deliberately. The fire service say that their resources are stretched to the limit every years as they attempt to deal with the fires. Destruction: School children on their Easter holidays have been blamed for a spate of hundreds of wild fires across beauty spots in Wales Brave: The dramatic scenes show a fireman beating at the fire in an attempt to put out the flames Although it is difficult to determine, those involved in fighting the fires believe that it is local youths who are off school who are responsible for the fires. To help combat the problem the local fire service launched a campaign called Project Bernie. It aims to explain the impact that fires in the area can have to local the local people, and the environment. Project Bernie uses a combination of social marketing techniques in education and enforcement to address the issue of deliberate grass fires. Project Bernie: The local fire service has launched a campaign to raise awareness of the impact that the fires have on the environment and people of the area Group Manager Rob Morris, Head of Community Safety and Partnerships for South Wales Fire and Rescue Service said: 'The people responsible for starting these types of fires need to understand that the fires severely damage much of the countryside surrounding their communities and they are putting lives in danger as it can take us a few minutes longer to respond to incidents in the towns and villages of Caerphilly county borough if we are on top of a mountain tackling a forest fire.' Project Bernie uses 'Bernie' the cartoon sheep as its logo, together with the strapline 'Grass is green, Fire is mean'.