New Delhi, May 2 -- Fuel costs for migrant workers, community kitchens, canteens, roadside dhabas and industrial users surged by over 47% on Friday as state-run oil companies raised prices of commercial liquefied petroleum gas by Rs.993 per 19-kg refill and Rs.261.50 per 5-kg cylinder. Public sector oil marketing companies also raised aviation turbine fuel prices for foreign airlines from May 1. ATF for international carriers was raised by $76.55 per kilolitre to $1,511.86 per KL, a 5.3% increase. Bulk diesel prices were raised 8.75%, from Rs.137 per litre to Rs.149, for bulk buyers including railways, state roadways, telecom towers, and infrastructure, construction, mining and agriculture sectors. Bulk diesel is not sold at retail pumps. The 19-kg commercial LPG cylinder - used by hotels, dhabas, canteens and industrial kitchens - now costs Rs.3,071.50, up from Rs.2,078.50. The 5-kg free trade LPG cylinder, used primarily by migrant labourers and students living near educational institutions, jumped from Rs.549 to Rs.810.50. The price changes brought back focus on energy costs with fears that dearer gas could be a precursor to increases in prices of petrol and diesel -- a move that the government denied was being considered till as recently as Tuesday. At least three sector experts, pointing to uncertain global energy supply and price volatility since the West Asia war broke out on February 28, said the commercial LPG user base was not homogeneous - and that not all of them could absorb the price shock or pass it on to customers. Worst affected are migrant labourers, who may return to their villages where firewood is far cheaper than the 5-kg cylinders many already procure from the black market at a premium. "There could be a reverse migration if the fuel cost does not make any economic sense for them, which will adversely impact construction and manufacturing. At least in their village, they have the guarantee of MGNREGA," one of them said, requesting anonymity. Chandan Poddar, a 25-year-old painter sharing a rented room in Delhi with nine other migrant workers, said his group had already beenspending close to Rs.3,000 collectively on 5-kg cylinders every month - and the latest increase had broken the economics entirely....