Bus drivers on cross-border routes were warned to watch their speed on mainland roads yesterday after 10 SAR residents were hurt in a weekend crash which killed the driver and a mainland passenger. Eight of the Hong Kong residents returned for treatment at Northern District Hospital after the Sunday lunchtime crash when their bus overturned on a stretch of the Guangzhou-Shenzhen Superhighway. 'We have sent a memo to our drivers urging them to watch their speed carefully as well as the road conditions,' said a spokesman for Guangdong (Hong Kong) Tours, which operates daily services between Hong Kong and Guangzhou. Buses reach a maximum speed of 110km/h but accidents had been rare over the years, the company said. 'Most recent accidents involved mainland operators, which import high-powered buses that do at least 140 to 150km/h as they try to compete with each other,' the spokesman said.