Collocations for detain - verb

briefly
He was kidnapped and briefly detained by a terrorist group.

indefinitely
Prisoners cannot be detained indefinitely without charge.

illegally

need not (esp. BrE)
This issue need not detain us long.

for
She was arrested and detained for distributing pro-democracy leaflets.

in connection with
Over 60 people have been detained in connection with the coup attempt.

be detained in custody, be detained in hospital (both BrE)
Two people were detained in hospital following the crash.

detain sb without charge, detain sb without trial
He has been detained without trial for nearly two years now.

Detain is used with these nouns as the subject:
authority, police

Detain is used with these nouns as the object:
alien, immigrant, prisoner, suspect