A clerk at an east side convenience store opened fire on customers overnight, Newsradio 1200 WOAI reports.

  It happened in the 4300 block of East Houston.

  Police say several men who had been in a dispute over paying for beer, opened fire on the store.

  The store clerk fired back and told police he thinks he hit one of the men.

  Police didn't find any victims, but they did find a blood trail leading away from the scene, and are checking local hospital.

  The clerk was not hurt.