GENEVA (Reuters) - The United Nations asked in vain for warring sides in Syria to stop attacking an aid convoy, the U.N. Syria and regional humanitarian coordinators said in a statement on Tuesday.

"The U.N. in Syria was informed of the attacks as they unfolded. Despite our efforts and communications with parties to the conflict, further attacks continued throughout the night, hampering efforts to reach and attend to the wounded," the statement by the coordinators, Massimo Diana and Kevin Kennedy, said.

An original version of the statement referred to "air strikes" rather than "attacks", but it was amended within minutes.

A U.N. spokesman said the error was probably due to a drafting mistake and it did not reflect a shift in the U.N.'s view of the incident.

"The explanation is that we are not in a position to determine whether these were in fact air strikes. We are in a position to say that the convoy was attacked," said Jens Laerke, U.N. humanitarian spokesman in Geneva.

"We have asked for an investigation of this, and that includes how to describe the attack."

However, he rejected a theory put forward by the Russian defense ministry that the convoy caught fire.

"We have designated it as an attack and that stands," he said. "We’ve established it was not a fire."

(Reporting by Tom Miles; Editing by Richard Balmforth)