Sgt. Kevin Chance said the birthday party was at JT's Lounge on Avenue F and 24th Street.
Police said that around midnight, an altercation happened, and then shots were fired.
Investigators have been canvassing the scene for several hours and said five to seven victims were shot and taken to two different hospitals. Their conditions are not known right now.
Dickinson PD, Dickinson Fire, and the Galveston County Sheriff's Office all responded to the scene.
Sgt. Chance said there is currently no one in custody.
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