A week after China fired flares at Vietnamese fishing boats  in yet another stand-off in the South China Sea, the two countries showed they could quietly co-operate in another field.
Fugitive stockbroker Zhang Fulin from Wenzhou, Zhejiang, was extradited to China , where he faces embezzlement charges. Along with his wife, he went on the run with 30 million yuan (HK$37.5 million) which police say are illegal funds.
While this is not the first extradition of a suspect from Vietnam to China, it is one of the first after both nations’ police forces signed an agreement  on extraditions in January.
The easy to cross 1,350km long border has allowed smuggling and trafficking to flourish and it seems to be increasing.
Police in Luoding busted a drug-smuggling ring from Vietnam this week, arresting three Vietnamese and four Chinese citizens, the Yangcheng Evening News reported . They were smuggling heroin and crystal meth from Vietnam through Guangxi to Guangdong.
As Chinese fugitives seek refuge in Vietnam, more Vietnamese migrant workers seek work in China’s better-paying factories.
The border province Guangxi says it arrested some 2,000 illegal immigrants from Vietnam in 2010. The number increased to almost 3,000 in 2011.
Some 2,600 people were caught only in the first half of last year, the last figures available .
Earlier this month, police in Shenzhen arrested 33 Vietnamese  who were on their way to work illegally in Fujian province.
Another 48 Vietnamese were arrested in Zhuhai  the week before. They had paid Chinese smugglers 1,000 yuan (HK$1,250) each to be taken to factories in Shantou.
Last month, a Guangdong bus with Vietnamese workers was stopped at a routine inspection  in Fangchenggang, Guangxi. The 25 illegal workers who were arrested are among the 359 Vietnamese illegal immigrants arrested in the city  in the first two months of 2013.