More than 300,000 people had crossed the border into China for the holiday weekend by last night. The exodus began on Thursday when immigration officers at Lowu recorded a total of 179,000 people entering China. By late last night another 121,000 had entered the mainland, with the checkpoint due to stay open until 11.30pm. In Hong Kong, the Chung Yeung festival was marked by four separate incidents of people being stung by bees as they visited rural areas to sweep ancestors' graves. A three-year-old girl, her mother and eight relatives were stung by a swarm of bees in Sai Kung Country Park. The family was on its way to an ancestor's grave at about 11am when one of them accidentally touched a beehive on a hillside near the west dam of High Island Reservoir. Six people, including the girl and her 35-year-old mother, needed hospital treatment after being stung on their hands, legs and faces. About two hours later, a 33-year-old man was attacked by bees in Tai Au Mun Road, where he was flying a model plane. Last night, he was in an observation ward in Tseung Kwan O Hospital. In Tuen Mun, a mainland man, 28, was stung on the head by a bee while cleaning up the garden of a village house in Siu Sau Village, Castle Peak Road. He was in stable condition in Tuen Mun Hospital. A man and woman, both 22, were airlifted to Pamela Youde Nethersole Eastern Hospital after being stung by bees on Lamma Island. The pair were attacked in So Kwu Wan at about 3.30pm and stung on the arms, legs and bodies. The man was last night in stable condition while the woman was treated and discharged. There were a total of 34 hill fires during yesterday's holiday, 29 in the New Territories, three in Kowloon and two on Hong Kong Island, a spokesman for the Fire Service said. Three people were arrested in an urn cemetery in Chai Wan when a fight broke out during grave-sweeping. A 47-year-old man and a relative, 51, began to fight with a 41-year-old man after getting into a quarrel when some personal items went missing. The relative and the 41-year-old man were treated in hospital for injuries. The three men were later taken to Chai Wan police station for inquiries.