deadly
enemy

lay, prepare, set up
The soldiers set up an ambush on the road.

carry out, spring, stage
They staged an ambush on an army patrol.

be caught in, run into, walk into
We ran into an ambush in the valley.

take place

in an/the ambush
Twelve men were killed in the ambush.

ambush on
an ambush on an army patrol

lie in ambush, wait in ambush
The soldiers lay in ambush for the enemy troops.

Ambush is used with these nouns as the object:
convoy, patrol