All work, little paws in sniffer dog training

After four weeks of intense training, Dag, a 3-year-old German shepherd, was still a bit clumsy when he was put to the test to locate heroin hidden in one of 12 cardboard boxes on a hot summer day at the General Administration of Customs' training center for detector dogs in Beijing.

When he eventually found the drugs after twice going through the boxes, which had been punched with holes, he failed to sit down quietly - the correct signal to alert his handler.

"Dag still has a long way to go to become a qualified sniffer dog for China Customs," said Hou Qinglong, from Qingdao, Shandong province, a customs officer and the animal's handler.