All flights in and out of one of London‘s airports have been cancelled after workers unearthed an unexploded explosive device in the Thames nearby.

As the ABC is reporting, it’s estimated that over 16,000 people will be affected after London City Airport went into a total shutdown as efforts were made to extract the World War II-era ordnance.

A spokesperson for London’s Metropolitan Police said the explosive was found as part of work being done on the airport:

The ordnance was discovered as part of pre-planned work at London City Airport and reported to the police at 5.06am on Sunday.

At 10pm an operational decision was made with the Royal Navy to implement a 214m exclusion zone to ensure that the ordnance can be safely dealt with whilst limiting any risk to the public.

CEO of London City Airport Robert Sinclar issued a statement to Twitter telling people to absolutely not come to the airport to try catch their flight:

The airport remains closed this morning following the discovery of a World War Two ordnance in King George V Dock on Sunday. All flights in and out of London City on Monday are cancelled and an exclusion zone is in place in the immediate area. I urge any passengers due to fly today not to come to the airport and to contact their airline for further information. I recognise this is causing inconvenience for our passengers, and in particular some of our local residents. The airport is cooperating fully with the Met Police and Royal Navy and working hard to safely remove the device and resolve the situation as quickly as possible.

A number of airlines have relocated their flights to Southend Airport, east of the city.