Night-shift New Territories taxi drivers have been warned to be on the lookout for two robbers after a spate of knifepoint attacks in the past month. The warning, from 12 taxi unions, came after a taxi driver was robbed of $900 and a mobile phone worth about $1,000 in Yuen Long early yesterday. A man got into his cab in Castle Peak Road, near Hung Shui Kiu, and asked the 46-year-old driver to take him to Tin Sum Tsuen. When the cab arrived in Tin Ha Road, an accomplice was waiting and the pair robbed the victim at knifepoint.