ASTANA, May 29 (Reuters) - Production at the Tengiz oilfield temporarily declined on May 28 due to an "operational disruption", Kazakhstan's energy ministry said.

The ministry added that oil output is now being restored and there are no risks to the environment or staff.

Oil production at the Chevron-led CVX.N Tengiz field, Kazakhstan's largest, fell sharply on May 26 as a result of an accident, two industry sources told Reuters on Friday.