Uzbek president Islam Karimov arrived here Wednesday afternoon to attend the summit of the Shanghai Cooperation Organization (SCO) slated for Thursday.

"The SCO is playing an increasingly important role in maintaining security within the SCO region," Karimov said in an interview with Chinese media ahead of the SCO summit.

With Uzbekistan added to the Shanghai Five mechanism which had grouped China, Kazakhstan, Kyrgyzstan, Russia and Tajikistan, the SCO came into being in June 2001.

The SCO anti-terrorism center is based in Tashkent, capital of Uzbeksitan.

Kazakh President Nursultan Nazarbayev and Tajik President Emomali Rakhmonov arrived in Shanghai earlier.

Kyrgyz President Kurmanbek Bakiyev and Russian President Vladimir Putin will arrive later Wednesday afternoon.