They were born June 11 at 4:31 p.m. at 5 pounds, 11 ounces, officials at the Royal Devon and Exeter Hospital.
The mother, Samantha Heal, 22, of Wonford, Devon, told The Daily Telegraph officials reported that twins born at the same time and weight was "unheard of" in Britain.
Cesarean twins would normally be born at least two minutes apart but the girls arrived within seconds of each other, so each had the same birth time, the hospital said.
Copyright 2009 by United Press International.