A group of activists brought holiday traffic to a standstill early Friday when they locked themselves together and lay down on a multilane slip road leading to Heathrow, Europe's busiest airport.

Police said they had arrested 10 people who had assembled on the M4 road, adding that one lane was still closed as of midday (1100 UTC). Authorities said the airport and surrounding road network were otherwise operating as normal.

A further five protesters were taken into custody for blocking a highway to Birmingham's airport, 160 kilometers (100 miles) north of London.

"This morning we shut down major transport hubs because the conventional avenues to justice have been shut down to us," the Black Lives Matter UK group said on Twitter.

Demonstrations were also held in east London, Manchester and Nottingham.

Nationwide shutdown

The Black Lives Matter protest movement began in the United States in response to fatal shootings of black people at the hands of white police officers. Joshua Virasami from the UK branch of the group told the BBC the movement was also needed "in Britain and all over the world."

In a statement, the group called for a “shutdown” of roads across the UK to "mourn those who have died in custody and to protest the ongoing racist violence of the police, border enforcement, structural inequalities and the everyday indignity of street racism."

Friday's protests were timed to coincide with the anniversary of the 2011 police shooting of 29-year-old Mark Duggan, whose death sparked days of rioting across the country.

nm/kl (Reuters, AFP, AP, dpa)