The incidents occurred in the 7th Police District, which includes large portions of Southeast Washington, and involved arrests and seizures of ammunition as well as guns.
The most recent occurred Saturday in the 3500 block of 23rd Street SE, according to D.C. police. About 4 p.m., police said they seized the Uzi, which they described as a machine gun, and two handguns, a .38-caliber revolver and a .38-caliber pistol.
Police said one person was arrested and a substantial amount of phencyclidine was also found. Phencyclidine, known as PCP, is a synthetic drug considered to have dangerous psychological effects.
It was not clear what led members of the 7th District vice unit to the 23rd Street address.
The day before, police said, two weapons were recovered after officers, including members of a robbery patrol unit, were sent to the 400 block of Condon Terrace SE. They were sent to investigate information about a man with a gun, police said.
As officers focused their attention on a building in the block, police said, they saw somebody walk out of the building.
When officers tried to make contact, the person began to run, police said, and stumbled off the curb. As he did, police said, several items fell into the road.
One of them was a black 9mm semiautomatic pistol. It had 18 rounds in its magazine and one in its chamber, police said.
The person who dropped the pistol was taken into custody, police said, and a 9mm round was found in his pocket.
Officers began searching the area, police said, and found another gun, a .45-caliber semiautomatic pistol. It had nine rounds in its magazine and one in its chamber, police said.
Police said they are continuing to investigate that incident.
On Jan. 8, police said, a robbery unit was on a patrol on Newcomb Street SE.
When the officers drove into the 400 block, they spotted some people, one of whom clutched his waistband and began to run. Police ran after him.
During the chase, police said they saw a 9mm pistol being flung aside. They said the gun was loaded, and its serial numbers had been obliterated.
The person who dropped the gun was on probation in a robbery case, police said.