MOSCOW, July 7 (Xinhuanet) -- Russia condemned the attacks Thursday on London's public transport system, which killed at least 33 people and injured hundreds more, and the authorities strengthened security in the transport system to ward off possible similar attacks.

    President Vladimir Putin, who is in Britain for the G8 summit Thursday, condemned the deadly blasts at London's public transport system as "an enormous crime," saying the world is "doing too little" to achieve unity in fighting terrorism, the Interfax news agency reported.

    Simultaneous explosions rocked at least three London subway trains and ripped apart a double-decker bus during the morning rush hour, killing at least 33 people and injuring more than 360, police said.

    "No matter where such inhuman crimes take place -- in London, New York, Moscow or in any other place -- they deserve unconditional condemnation and call for the unity of all civilized countries in combating international terrorism," Putin said in Gleneagles, Scotland.

    "What has happened is fresh evidence that all of us are doing too little to pool our efforts in the most effective way in combating terrorism," Putin said.

    Prime Minister Mikhail Fradkov, who described the explosions in London as "a world-scale tragedy," urged joint efforts worldwide in fighting terror.

    "Combating terrorism is a burning issue that calls for joint efforts on the part of all countries," Fradkov said. "We must not forget this for a single day."

    Russian police and Interior Ministry troops were put on high alert in the wake of the deadly blasts in London, the Itar-Tass news agency reported.

    "Emergency measures have been taken to prevent possible terrorist acts on planes and railways," First Deputy Interior Minister Alexander Chekalin told reporters.

    Police patrols have been beefed up at the Moscow subway and baggage and passenger checks have become more rigorous at airports, Chekalin said. Passport and migration controls have been tightened and road police posts reinforced, he added.

    Moscow's subway has also fallen prey to repeated attacks in its70-year history. A blast on Feb. 6, 2004 killed 40 people and injured more than 130. Enditem