BAYONNE, N.J. (CBSNewYork) — Three workers were hurt Wednesday morning in a small explosion in Bayonne, New Jersey.

It happened around 9 a.m. on Goldsborough Drive and Chosin Few Way as contractors working for PSE&G were in the process of installing a new gas line.

PSE&G said the workers were conducting an air pressure test on the pipe, which is standard practice, when there was an explosion.

Police said two workers were seriously hurt while a third suffered minor injuries. They were taken to Jersey City Medical Center.

Two officers who were on the scene directing traffic as the work was being done also went to the hospital with minor injuries. Their vehicle could be seen completely covered with dirt, CBS2’s Meg Baker reported.

Officials said natural gas was not flowing through the main at the time and said it is still not clear what caused the explosion.

The investigation is ongoing.

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