The Secretary-General of the Shanghai Cooperation Organization (SCO), Zhang Deguang, sent a message Monday to Russian Foreign Minister Sergei Lavrov, condemning the terrorist attacks behind the downing last week of two Russian airliners.

In the message Zhang said he strongly condemned the terrorist acts and offered condolences to families of the victims.

The SCO is opposed to any form of terrorism and firmly supports the Russian government's policies and operations to combat terrorism and to maintain sovereignty and territorial integrity, Zhang said.

Zhang said the SCO is willing to further step-up cooperation amongst its member countries on security to fight terrorism, separatism and extremism and to safeguard regional peace and stability.

The SCO, a regional cooperation body set up in June 2001, groups China, Russia, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan.

Two Russian passenger jets crashed almost simultaneously last Tuesday night after taking off from Moscow's Domodedovo Airport killing all 90 people on board.

Security service officials believe both planes were brought down by explosions, Russian news agencies reported Monday.

The crashes came five days ahead of Sunday's presidential election in the Russian breakaway republic of Chechnya where separatist rebels have been blamed for a series of terror activities that have claimed hundreds of lives.