cordon
A police cordon was set up as forensic teams searched for further evidence.
They dragged him behind a police cordon so that he could receive medical attention.
The protesters made a half-hearted attempt to break through the police cordon.

SMART Vocabulary: related words and phrases

The police generally
anti-police
anti-riot
baton
baton charge
billy club
booze bus
escort
fuzz
gendarmerie
Interpol
kettle
kettling
lathi
precinct
Scotland Yard
secret police
self-policing
Special Branch
the Royal Canadian Mounted Police
warrant