LETHBRIDGE, Alta. - Amorous couples looking to unite in the great outdoors should think twice in one southern Alberta city.

Police in Lethbridge are increasing patrols and the city is removing trees, branches and brush from its river valley to curb what authorities are calling indecent activity.

Police say they have been called out multiple times in the last few months to deal with couples having sex in green spaces.

They say the acts have been in full view of park users and have also been observed by officers on patrol.

So far, only warnings have been issued.

But police say criminal charges will be considered on a case-by-case basis.