* Hang Seng index ends down 1.28% * China Enterprises index HSCE falls 1.04% * HSI financial sub-index is down 2%; property sector slips 0.6% HONG KONG, May 3 (Reuters) - Hong Kong stocks fell on Monday, due to profit-booking after a recent rally in subdued trading as the Chinese markets were closed for holidays, while rising COVID-19 cases in the region raised concerns of more measures and deeper economic pain. ** The Hang Seng index closed down 367.34 points, or 1.28%, at 28,357.54, its lowest closing since March 29. The Hang Seng China Enterprises index fell 1.04% to 10,713. ** After identifying a cluster of COVID-19 cases over the weekend, Singapore tightened social distancing controls. ** The Hong Kong Monetary Authority, the key manager of Hong Kong’s Exchange Fund, said slow vaccination take up in the city could hinder its competitiveness as a business centre. ** The sub-index of the Hang Seng tracking energy shares dipped 0.1%, while IT, financials and property sectors ended 0.53%, 2.04% and 0.57% lower, respectively. ** China’s stock and bond markets, as well as its foreign exchange and commodity futures markets are closed on May 1-5 for the Labour Day holiday. ** “Investors were not even interested in hunting for bargain when markets like Japan and China were on holiday,” said Steven Leung, a sales director at UOB Kay Hian, adding, concern over further measures from China’s regulators aiming at new economy stocks also kept investors away. ** The top gainer on the Hang Seng was China Petroleum & Chemical Corp, up 1.29%, while the biggest loser was China Mengniu Dairy Co Ltd, dropping 3.49%. ** Around the region, MSCI’s Asia ex-Japan stock index was weaker by 0.73% ** The top gainers among H-shares were Anhui Conch Cement Co Ltd up 1.94%, followed by Hansoh Pharmaceutical Group Company Ltd, gaining 1.49% and Postal Savings Bank of China Co Ltd, up by 1.38%. ** The three biggest H-shares percentage decliners were China Mengniu Dairy Co Ltd, down 3.49%, China Feihe Ltd, falling 2.93% and Alibaba Health Information Technology Ltd, down 2.53%. (Reporting by Donny Kwok; Editing by Rashmi Aich) Our Standards: The Thomson Reuters Trust Principles.