BEIRUT, May 12 (Reuters) - The Red Cross said an aid convoy was refused entry to a besieged Syrian town on Thursday, blocking what would have been the first supplies for its residents for more than three years.

The town of Daraya, on the outskirts of Damascus, is held by rebels and has long been under siege by government forces and their allies.

The United Nations said this month Syria’s government was refusing U.N. demands to deliver aid to hundreds of thousands of people. There are almost 500,000 Syrians trapped and cut off from aid by warring sides including the government, insurgents and Islamic State, the United Nations says. (Reporting by John Davison)