Chinese soldiers raise a national flag on Heixiazi Island, where Chinese and Russian diplomats unveiled boundary markers for the eastern section of the two countries' border at a ceremony on October 14.

The island, known as Bolshoi Ussuriysky Island in Russia, is at the confluence of the Heilongjiang and Wusulijiang rivers that serve as the natural border between China and Russia.

After 40 years of negotiation, China and Russia finished boundary demarcation work and signed an agreement in July 2008.

Chinese and Russian foreign ministries confirmed on October 14 that, through an exchange of notes, the additional protocol between China and Russia on the eastern section of their boundary and its appendix have officially taken effect.