A man was arrested by police investigating a suspect bag which temporarily closed Stansted Airport.
Various parts of the airport were cordoned off
Bomb disposal experts checked the bag, found near the entrance shortly before 1900 BST, but later concluded it was "not suspicious".
A police spokeswoman said the airport was operating normally from 2035 BST and there was no cause for concern.
The alert came after police stepped up their presence at Stansted following incidents in Glasgow and London.
"A man was arrested when he returned to the bag and said it was his property.
"Police had some concerns over the contents of the bag so the man was detained for questioning," said a police spokeswoman.
A cordon was placed around the bag.
Police said one man had been arrested and was being held - but not on suspicion of terror offences.
BBC Radio Cambridgeshire reporter Emma McLean, who was on a flight to Stansted from Edinburgh, said no one was being allowed in or out of the airport for a time.
Ms McLean said earlier: "Police officers started cordoning off various parts of the airport.
"There must be a couple of hundred people here waiting to leave the airport.
"From what I understand flights are still departing from the airport but people can't get in and out of the airport.
"Police have just told us a package was found at the front of the airport."
Roddy MacPhee, 64, who had flown to Stansted from Glasgow said: "There is an armed response unit, sniffer dogs, a bomb disposal unit and the fire brigade here.
"Passengers are being pretty patient, but we are unaware of what has happened."