The continued detention of four Rio Tinto employees in China, including Australian national Stern Hu, looks likely to become a very sticky diplomatic situation for Kevin Rudd.

Rio’s China crisis escalates. The affair could take several paths from here and most of them lead to places Rio and the Australian Government do not want to be. — Malcolm Maiden, The Sydney Morning Herald

Lack of evidence adds to the mystery. Would being stronger in language be more appropriate and get better results, or simply make things worse? — Michelle Grattan, The Age

Big risk in nasty business. What does the much touted Australia-China relationship add up to if Beijing treats Canberra with such conspicuous discourtesy and indifference? Greg Sheridan, The Australian

China cannot afford to be vengeful. If China wants to take its rightful place at the top table of international economics and trade, it can’t be seen to be playing those sort of games. — David Prosser, The Independent

Country vs Company. Where does your loyalty lie? For Beijing, there is simply no question. If you are Chinese — or a foreign passport holder of Chinese origin — you work for China first, second and third. — Alexander Smith, Reuters

A challenge to Rudd. Given the respect Howard had in the region … China would have thought twice about such a move under his prime ministerial leadership. — Right Pulse

We have evidence. Rio employees “held for espionage — China Daily

The law will be followed. China to handle spy case of Rio Tinto employees “according to the law” — Xinhua