LONDON — Chanting, “Detention centers — shut them down” and “Asylum seekers have the right — here to stay, here to fight,” more than 80 people demonstrated at the Harmondsworth Immigration Removal Centre near Heathrow Airport here Nov. 8.

The U.K. government holds for indefinite periods between 2,000 and 3,000 people, including children, in Immigration Removal Centres.

Protesters also drew attention to the U.K. Foreign Office’s recent announcement that it will no longer support search and rescue operations for refugees drowning in the Mediterranean Sea. More than 2,500 people are known to have drowned or gone missing in the Mediterranean so far this year. Around 150,000 have been rescued since October 2013.