Two people have been arrested in connection with the “criminal use of drones” after allegedly causing a standstill at one of London’s busiest airports, British police said Saturday.

“As part of our ongoing investigations into the criminal use of drones which has severely disrupted flights in and out of Gatwick Airport, Sussex Police made two arrests just after 10 p.m. on 21 December,” Superintendent James Collis said.

He said investigations are still continuing as well as police activity “to build resilience to detect and mitigate further incursions from drones, by deploying a range of tactics”.

Up to 1,000 aircraft had been cancelled or diverted after drone activity was detected since Wednesday and nearly 140,000 passengers were affected in one of the busiest times of the year.

Appealing to public for more information, Collis said: “The arrests we have made this evening are a result of our determination to keep the public safe from harm, every line of enquiry will remain open to us until we are confident that we have mitigated further threats to the safety of passengers.”

Gatwick airport officials said on Saturday morning that it was open for flights but urged passengers to check with their airline before travelling.

A spokesman said the runway is open and 757 flights will continue as scheduled on Saturday.