A 19-year-old man was shot in the leg outside a house party near Lake Merced on Saturday night, according to police.

The teenager and his friends were involved in an argument with another group at around 11:45 p.m. when the shooter fired a gun, police said Monday. Police did not say where the shooting happened.

A friend drove the teenager to Zuckerberg San Francisco General Hospital, where he was treated for a gunshot wound to the left leg. He is expected to survive.

Police said the suspect in the shooting is unknown.

mbarba@sfexaminer.com