Flights at London City Airport have been disrupted after the Black Lives Matter campaign group gained access to the runway.
Met Police were called at 5.40am on Tuesday (September 6) and patrol cars and officers made their way on to the Tarmac at the Docklands hub trying to resolve the protest, with nine protesters huddled together clutching banners.
The airport said inbound flights were being diverted and it hoped to “resume operations as soon as possible”.
A Met Police spokesman said: "They have erected a tripod and have locked themselves together.
"Officers are currently on scene and are negotiating with them. We are awaiting the arrival of specialist resources that are able to 'unlock' the protesters."
Seven people have been arrested while two remain on the runway. Inbound flights are being diverted and the group has said it will stay on the runway "as long as feasibly possible".
A spokesman for the airport confirmed on Twitter at 11.30am that the runway had been cleared, adding: "We are preparing the airfield to resume operations as soon as possible". It re-opened at midday.
The protest is a carbon copy of the assault on Heathrow airport where travellers were disrupted on August 5 by a cordon of blocking roads with banners and their own bodies.
Black Lives Matter UK tweeted: “Activists in support of BLMUK #Shutdown London City Airport to protest the UK’s environmental impact on black people.”
In a further post, it said: “At London City Airport a small elite is able to fly, in 2016 alone 3,176 migrants have died or gone missing in the Mediterranean #Shutdown.”
In a statement, the group said: "Recently London City Airport was given approval to expand its capacity, a move that consigns the local community in Newham to further deterioration of their environment. Seven out of 10 of the countries most affected by climate change are in sub-Saharan Africa."
It also references "charter flights" to "remove black people from the country based on their immigration status".
Speaking to BBC London, activist Joshua Virasami said: "The community where this airport is is a predominantly black community.
"In Britain, 28% of black people are more likely to be exposed to air pollution being in closest proximity to the industries causing climate change."
He said the disruption was "a very small inconvenience when you think about the consequences for black communities daily" and the protesters would remain on site "as long as feasibly possible".
Black Lives Matter UK has taken its inspiration from a similar movement in the US which has arisen from the number of black people shot and killed by police. In the UK, it has taken on a number of causes and targeted operations aimed at causing maximum disruption, regardless of their link to the root cause.
Passenger Chanel de Kock told the Press Association she was stuck for three-and-a-half hours.
She said: "The flight information boards had no information, and there wasn't any information given by the airport, this was really frustrating for passengers. Then standing in queues for hours to check out, then only given a pamphlet to call the airline.
"I wish the airport would tighten their security as it's a bit worrying that people can access the runway so easily in the current state of our times, and also that the airport will be better at giving information to people at the airport.
"It was absolute chaos and really badly handled by what I thought was my favourite airport."
The Metropolitan Police said this morning that they were investigating how the group reached the runway amid reports that they had sailed across the dock in a rubber dinghy.
Black Lives Matter UK spokesman Jacob Oti, 22, said: "This has highlighted important issues which people need to think about.
He declined to go into detail about how the protesters gained access to the site, but confirmed it was via the Thames.
The protest comes on a bad day for British Airways, which has apologised to passengers for delays after an IT glitch hit check-in systems.
Passengers complained of hours queuing at Heathrow and Gatwick. A spokeswoman confirmed passengers were being checked in "a bit slower than usual".