Protesters held a fourth Surround Harmondsworth demonstration at the immigration detention centre near Heathrow airport last Saturday.
They are demanding an end to fast track deportations of migrants and calling for immigration removal centres to be closed.
The Home Office said an independent investigation has been launched into the death of Rubel Ahmed in Morton Hall detention centre in Lincolnshire earlier this month.
The authorities now admit that rioting the morning after Rubel’s death went on for 12 and a half hours.
A three-day political festival
