Cooperation between police on the Chinese mainland and Taiwan has reduced crime on both sides, a mainland spokesman said on Wednesday.

The mainland and Taiwan signed the Agreement on Cross-Straits Mutual Assistance in Cracking Down on Crime in April 2009 in Nanjing, Jiangsu province. Since then, police on either side of the Taiwan Straits have set up multilevel contact.

Crime has declined by 50 percent in Taiwan and in several provinces on the mainland, said Yang Yi, spokesman for the Taiwan Affairs Office of the State Council, China's cabinet.