The bodies were pulled from the debris yesterday after four blasts rocked the Prvi Partizan plant in Uzice, police official Predrag Maric said on B92 television, adding that firefighters had put out the resulting blaze.
Ten people suffered light injuries and had been taken to hospital, said Zoran Lazovic, a doctor at Uzice's hospital.
Town mayor Jovan Markovic said the explosions occurred at around 0300 IST.
The Prvi Partizan factory, which employs around 600 people, has manufactured ammunition for nearly 80 years for the Serbian military and police, as well as foreign armies. It also produces ammunition for hunters.
The cause of the explosions was not immediately known.
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