The U.N. humanitarian chief Mark Lowcock urged the Security Council yesterday to take action to end the "bloody onslaught" in Syria's last opposition-held stronghold, warning that continued violence could create the worst humanitarian disaster of the 21st century.<br />''<br />''Mr Lowcock told council members they have ignored previous pleas to stop the bombing and shelling in Idlib province by Syrian and Russian warplanes.<br />''<br />''The Security Council has been deeply divided over the Syrian conflict since it began in 2011, with Russia backing the government and Western nations supporting the opposition.<br />''<br />'' Due to this, U.N.'s most powerful body could not take any significant action.<br />''<br />''<br />''<br />