AMSTERDAM, Nether-lands—Amsterdam’s Schiphol Airport has closed one of its five runways after a World War II bomb was unearthed during excavations nearby.

Army explosives experts say the 500-pound (226-kilogram) British bomb must remain still for 54 hours because it was moved during its discovery by workers building a road.

Bert van Denham from the local municipality says the bomb is expected to be removed on Thursday.

Schiphol spokesman Kathelijne Vermeulen said Tuesday that flights are being diverted to other runways at the airport and no delays are expected.