WASHINGTON, Sept 20 (Reuters) - An attack on a convoy carrying humanitarian supplies in the Aleppo area of Syria appeared to be an air strike but it was not carried out by coalition jets, U.S. Central Command spokesman Colonel John Thomas said on Tuesday.

NEW YORK (Reuters) - Shares of Mylan NV are trading at historically low valuations as the company's chief executive officer is set to face a congressional grilling on Wednesday over the price of its EpiPen emergency allergy treatment.

UNITED NATIONS, Sept 20 (Reuters) - The United States sought to keep alive a ceasefire in Syria's civil war on Tuesday as other countries voiced skepticism that a U.S.-Russian deal to halt the violence could be revived.

NEW YORK, Sept 20 (Reuters) - Syria's chief opposition coordinator Riad Hijab said on Tuesday international efforts to achieve a ceasefire in Syria were doomed to fail without any credible mechanism to designate blame or attribute consequences.

MOSCOW, Sept 20 (Reuters) - Russia's defense ministry said on Tuesday an aid convoy that came under attack in Syria had been accompanied by a militants' pickup truck armed with a heavy mortar gun, Russian news agencies reported.

(Reuters) - Billionaire investor George Soros said on Tuesday, he would invest $500 million to meet the needs of migrants and refugees.

LONDON (Thomson Reuters Foundation) - The United Nations suspended all aid shipments into Syria on Tuesday after a deadly attack on a convoy carrying humanitarian supplies.

BENGHAZI, Libya (Reuters) - At least eight civilians including women and children were killed in an air strike near an oasis town in central Libya on Tuesday, a hospital doctor and an eyewitness said.

GENEVA, Sept 20 (Reuters) - The United Nations said on Tuesday that a Syrian humanitarian convoy was hit by "attacks" on Monday rather than "air strikes" as it had said earlier.