A pilot and a trainee pilot were aboard the helicopter when it came down at a spot located 100 km from Lahore.
The helicopter was on a routine flight from a base in Gujranwala when it lost contact with the control tower, official said.
According to Mumtaz Rathore, a correspondent of a TV news channel, witnesses said they had seen the small helicopter crashing into the Chenab river.
The fate of the pilots could not immediately be ascertained.
