Two people glued themselves to the gate of an immigration centre in an attempt to stop the departure of a deportation flight from the UK, a campaign group said.
Ten anti-deportation activists gathered to protest at Colnbrook immigration removal centre near Heathrow airport, said the Unity centre.
The protesters formed a blockade in a bid to stop a bus carrying deportees from the centre being taken to Stansted airport for a flight to Nigeria, Ghana and Sierra Leone, the group said.
Police attended the scene on Tuesday evening for around five and a half hours but no arrests were made.
London Fire Brigade also sent a fire engine to the scene.
A Metropolitan police spokesman said: “There were a small number of demonstrators in attendance at the immigration centre who had been there since 5.30pm.
“We were on the scene with the fire brigade in a monitoring role and there have been no arrests.”