Six construction workers have been taken to hospital after dozens of people got involved in a mass brawl on a site on Moscow’s outskirts, the Moskva city news agency reported on Wednesday, citing the Interior Ministry.

Approximately 40 workers, who mostly comprised of migrants from Uzbekistan and Armenia, were armed with spades, hammers and steel rods. No firearms were discharged during the incident, Moskva cited police as saying.

The quarrel reportedly began after several Uzbek workers threw rubbish from rooftops that fell on the heads of their co-workers. Police have launched a case on charges of hooliganism.