The shooting happened near the Northline area in the 400 block of West Parker Road at about 3:20 a.m.
Lt. Riley with HPD said several hundred people were standing outside the nightclub, which officials said appeared to be unlicensed, trying to get in.
There was a security guard who police said was handling a shotgun, and it misfired, causing bullets to ricochet and hit two women.
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One of the women was struck in the forehead, and a bullet hit the second woman in the abdomen and the shoulder, police said.
Both women were treated at the scene. Officials did not elaborate on their conditions.
HPD said the security guard fled the scene before police arrived.
Officials gave no additional details on the search for the guard or a physical description.
Investigators said that, in this instance, no incident required the guard to use his firearm.
An investigation is underway, HPD said.