Two men have been arrested at Heathrow as climate change protesters tried to launch drones within the airport’s exclusion zone.
Heathrow Pause said it intended to fly drones in the 5km exclusion zone around the airport on Friday morning.
Meanwhile, the first flights landed as normal just before 05:00 BST.
The Met Police said it was confident disruption would be kept to a minimum and a dispersal order has been put in place at the airport.
The two men were arrested on suspicion of conspiracy to commit a public nuisance the force said.
A large police presence has been seen around the airport, where the dispersal order will be in place until 04:30 on Sunday.
Deputy Assistant Commissioner Laurence Taylor said: “We are really clear that [flying drones] is unlawful, it is a criminal offence, and anybody who turns up expecting to fly drones in that exclusion zone will be arrested.”
The latest arrests followed five pre-emptive arrests on Thursday, when officers caught suspected would-be drone pilots, including Extinction Rebellion co-founder, Roger Hallam, ahead of the planned action.
Heathrow Pause is a splinter group of the wider Extinction Rebellion movement, although it operates independently from it and opposes the expansion of Heathrow.
A live Twitter stream apparently launched by protesters at Heathrow suggested two people had been struggling to get a drone off the ground.
Heathrow Pause claimed the airport were using “signal jamming to frustrate” early drone flights.
The protest is the latest in a string of climate change demonstrations this year, including the widespread action in London in April, which saw Extinction Rebellion bring sites including Oxford Circus and Waterloo Bridge to a standstill.
Heathrow Airport confirmed its runways were open adding it was committed to addressing climate change.
But added this was best tackled through “constructive engagement and working together to address the issue”.