Aug 24 (Reuters) - Hong Kong shares rose on Tuesday by their most in three weeks, as investors snapped up tech and healthcare stocks following a recent sell-off, but some market participants cautioned the rebound was likely to be short-lived. ** The Hang Seng index rose 2.5% to 25,727.92, while the China Enterprises Index gained 3.2% to 9,098.68. ** The Hang Seng TECH Index surged 7.1%, rebounding from the recent sell-off triggered by deepening fears over Beijing’s regulatory tightening. The index is still down about 40% from its February peak. ** “It’s mainly a rebound from last week’s sell-off, with some help from JD.com’s earnings,” said Alex Wong, director of asset management at Ample Capital. ** “But there might not be much room for imagination in the future, as the regulatory environment for Chinese tech companies is already different.” ** E-commerce giant JD.Com jumped 14.9% after its earnings results beat analysts’ expectations and the company added record new users in the second quarter. ** Tencent Holdings surged 8.8%, rising for the third day in a row, after the social-media giant bought back shares worth HK$100.0 million ($12.84 million) on Aug. 23, its third consecutive day of share buybacks. ** E-commerce behemoth Alibaba Group, which on Monday fell to its lowest level since its Hong Kong debut, bounced 9.5%. ** Food-delivery company Meituan surged 13.5%, the biggest daily gainer in the Hang Seng Index. ** The Hang Seng Healthcare index, also a target of recent sell-offs, rose 4.8%. Healthcare companies Wuxi Biologics and Alibaba Health Information Technology surged 7.7% and 6.4%, respectively. ** Wuxi Biologics said its net profit jumped 163% to 1.77 billion yuan ($273.1 million), while revenue surged 126.7% to 4.41 billion yuan. ($1 = 7.7893 Hong Kong dollars) (Reporting by the Shanghai Newsroom; Editing by Subhranshu Sahu) Our Standards: The Thomson Reuters Trust Principles.