The 800-year-old Serbian monastery of Helandari on Mount Athos was ravaged by a fire that broke out early yesterday morning and destroyed a large section of the complex, including 17th and 18th century frescoes. None of the 25 resident monks - all Serbs - were hurt, while the monastery's medieval heirlooms and holy relics were evacuated from a secret chamber with the help of ex-army special forces soldiers from a neighboring Greek monastery who rappelled down the 30-meter-high walls with ropes. The fire at Helandari - the northernmost of the 20 monasteries on the Athos peninsula - broke out at around 1 a.m. Stormy seas off Mt Athos prevented fire brigade forces stationed at Ierissos, Arnaia and Polygiros in Halkidiki from arriving on the spot until after dawn, by which time the monks had safely removed most of the heirlooms. After efforts that lasted several hours, some 60 firemen managed to bring the blaze under control while at the same time preventing the flames from spreading from the northeastern wing to the monastery church and the refectory with its 14th century frescoes. However, according to an announcement by the Serbian Orthodox Church, the gutted sections included the abbot's cell, the guest rooms - which had been built in 1821 and recently renovated - and the White Residence, erected in 1598, which was under general restoration. Greek officials said four chapels - with 17th and 18th century frescoes - were also destroyed. According to Polygiros Deputy Fire Chief Stylianos Ambaras, the fire is believed to have broken out in the abbot's dwelling, and was probably started by an electric heater. Late yesterday, much of the gutted section was still smouldering, and firemen remained on hand to prevent the fire from spreading again. The monastery contains a rich collection of icons and medieval heirlooms dating from the 11th century, as well as one of the most important collections of Slavic manuscripts in the world. Founded in 1198 by former Serbian ruler Stefan Nemanja (1132-1200) and his youngest son, Rastko - who both became monks and were canonized as Saints Simeon and Sava - following a grant by Byzantine Emperor Alexios III, Helandari is one of the holiest Serbian sanctuaries. Serbian Premier Vojislav Kostunica, who visited Helandari last summer, pledged to help restore the ravaged complex, while Serbian television appealed for donations. Apart from Serbian Helandari, there are also a Russian and a Bulgarian monastery on Mt Athos.