Two men who were arrested Saturday on gun charges after gang-unit officers stopped the cab they were in on Norwell Street attacked a man in the Dorchester District Court lockup while awaiting arraignment on Monday morning, the Suffolk County District Attorney's office reports.

Dijoun Beasley, 19, and Tyshawn Cummings, 20, both of Dorchester, were arrested Saturday afternoon after officers conducting an unrelated investigation on Norfolk Street noticed them come out of a house with one "clutching at the right side of his waist band area in an attempt to cover an unknown object."

The two got into a cab, which officers followed and then stopped on Norwell Street after the driver broke a traffic law, police say.

Both were charged with unlawful possession of a firearm, unlawful possession of ammunition, carrying a loaded firearm and possession of a firearm with an obliterated serial number, police say. Beasley was also charged with possession of crack cocaine with intent to distribute.

According to the DA's office, their attack on another man awaiting arraignment this morning means they will probably not be arraigned until Tuesday, because they had to be returned to District C-11 for booking and processing on a charge of assault and battery.

In October, Cummings won acquittal in at his trial on charges he and another man shot somebody in 2013. The other man pleaded guilty to the charges and is now serving five years in state prison, the DA's office reports.