ANKARA, Turkey (AP) — An explosion at a fireworks factory in northwestern Turkey injured at least 41 people Friday, officials and news reports said.

There were an estimated 150 workers at the factory outside the town of Hendek, in Sakarya province, Gov. Cetin Oktay Kaldirim told state-run Anadolu Agency.

At least 41 of them were hospitalized with injuries, he said, adding that no lives were lost. News reports said three workers were in serious condition.

Several firefighters and ambulances were sent to the factory, which is away from residential areas. However, explosions were continuing, hampering efforts to bring the fire under control.

The cause of the blast wasn't immediately known.

Earlier, television video showed a large, mushroom-shape cloud of smoke rising from the factory.

HaberTurk television said authorities blocked roads leading to the factory. Families rushed to the site for news of their loved ones.