AMSTERDAM – Authorities evacuated parts of Amsterdam's Schiphol airport Wednesday after workers found an unexploded World War Two bomb, forcing airlines to delay and cancel some flights. And separately, a flight from Malaga was surrounded by Dutch security forces upon landing at Schiphol after a lack of communication between the pilot and Dutch ground control caused a hijack scare. The Netherlands intercepted the Spanish airliner with two fighter planes and then sent security forces to surround it on the tarmac at Amsterdam's airport in a hijack scare caused by a loss of radio contact. The plane, flown by Spanish carrier Vueling from Malaga in Spain to Amsterdam with about 180 passengers on board, had lost radio contact with air traffic control, a spokesman for the military police said. “There was no communication with the crew at all,” Martijn Peelen, military police spokesman, said. “My colleagues are still talking to the (plane's) captain to find out what caused the communication failure.” Peelen said that as soon as the plane landed at Schiphol airport, it was surrounded by security forces and a negotiator was sent to talk to the crew. “After the negotiator spoke to the captain we were certain there were no hijackers on the plane,” Peelen said. The plane had been intercepted and escorted by two F-16 fighters sent by the Dutch Defense Ministry. “The scrambling of fighter jets was part of a standard emergency procedure after the plane failed to communicate,” said an official of the NATO Western military alliance. NATO's Combined Air Operations Center had notified the Dutch military after being alerted by air traffic controllers to the loss of contact. Passengers had to remain on board the plane for hours while it was searched by police, but were later allowed to disembark and board buses. “We first realized something was wrong when we started circling above Rotterdam over and over, and the captain told us there was some problem in Schiphol. We spent about four hours on the ground after arriving,” said Erna, a passenger, who asked that her surname not be used. A spokeswoman for the airline, Vueling, said: “There was never any danger. There was a lack of communication between the pilot and the tower and the airport has activated the security protocol.” The German bomb was discovered buried underground near the transport hub's busy Terminal C, which handles flights to most major European destinations, the Dutch Defence Ministry said in a statement. – Agencies