Russia on Wednesday warned Turkey against intervening in Syria as it blocked a UN bid to end the Damascus regime's brutal assault on the last rebel enclave. Syrian aid workers called urgently for a ceasefire and international help for nearly a million people fleeing the regime onslaught in the country's northwestern Idlib province -- the biggest wave of displaced civilians in the nine-year conflict. Turkey, supporter of some rebel groups in Idlib, has been pushing for a renewed ceasefire in talks with Russia, which backs the Syrian regime.