"Authorities have almost come up with detailed plans on the issue of extraditing criminals, and there is a good unspoken understanding between the two sides," said Lu Yu-jiun, who heads a group of 20 representatives from Taiwan in a seminar on police science that opens in Shanghai today.

"Crimes are the common enemy of human beings, and (attacking crime) will have far-reaching influences on cross-Straits relations," he said.

In future, the two sides will share information on crimes and conduct further co-operation on cracking down on crimes, he said, despite many issues yet to be tackled in cross-Straits communication.

Cross-Straits experts have long been calling for the mainland and Taiwan to join hands in cracking down on crimes such as financial fraud, human trafficking, smuggling, counterfeiting, and money laundering.

In the latest move, the Police Association of China sponsored the two-day seminar for representatives from the mainland, Taiwan, Hong Kong and Macao and will focus on the discussion of police sciences.

"The opening of the seminar reflects the common will of people from cross-Straits and compatriots from Hong Kong and Macao," said Tian Qiyu, a former vice-minister of Public Security and chairman of the association, yesterday when he met representatives from Hong Kong, Macao and Taiwan.

"In the past few years, police officers from cross-Straits, Hong Kong and Macao conducted effective co-operation on studying police science," he said.

But the seminar would be a new starting point for common efforts to attack crimes in the future, he added.

"The seminar is an academic one," Lu said, "but academic studies are combined with partnership on police affairs.

"We are seeking (the co-operation on police affairs)," he added.