The Mahad police on Saturday stopped illegal quarrying over the mouth of a Konkan Railway (KR) tunnel at Palkhewadi near Mahad, Raigad district. Police stepped in after villagers informed them about the illegal activity.The local administration and the Konkan Railway authorities said they were unaware about the quarrying, which included a series of blasts. Mahad taluka, a three-hour journey from Mumbai, is on the Ratnagiri-Madgaon route. The 4.5 km-long tunnel joining Palkhewadi and Nathuwadi was built on difficult terrain using state-of-the-art technology.Stones from the hill above the tunnel were being transported to Palkhewadi village, where contractor K.C. Chandani was building a road. The damage to the tunnel has not been ascertained. Konkan Railway Ways and Works director D.G. Diwate said he was unaware about the quarrying and said that he will send his engineers to inspect the tunnel. ‘‘I will only be able to comment when they report back,’’ he added.Mahad Tahsildar B.D. Patil said he had rejected an application for quarrying work over the tunnel. ‘‘The quarrying was illegal and has been halted,’’ he said.