Three men were shot, one fatally, on Wednesday night in Mattapan; at almost the same time, a shooting in Roxbury left two men dead and one injured, police said.

Officers responding to shots fired near 41 Hosmer St. at about 10:19 p.m. found the three men suffering from gunshot wounds. One victim, Darwin Adilas, 21, of Randolph, was pronounced dead at the scene.

According to police spokeswoman Rachel McGuire, the two additional male victims suffered non life threatening injuries and were taken to Boston Medical Center for treatment.

The victims were transported in serious condition, said a Boston EMS spokesman.

"These incidents do not appear to be random," McGuire said. She said the victims appear to have been targeted in connection with possible gang activity.

The shootings occurred on a particularly violent night in Boston, as two other men in their 20s were pronounced dead after being shot in Roxbury on Ernst Street at about 10:15 p.m.

One was taken to Brigham and Women’s Hospital, the second to Boston Medical Center. Both later succumbed to their injuries and were pronounced deceased at the hospitals, police said. Another victim from the Roxbury incident was taken to Beth Israel Deaconess Medical Center with non-life-threatening injuries, police said.

None of the victims were immediately identified.

Mayor Martin Walsh said in a statement: "I am extremely saddened and disturbed by the violence that took place overnight in our community; this has to stop. It is my utmost priority to ensure the safety of our residents and it is important that we continue to work together with families and youth throughout our neighborhoods, to get them on alternative pathways to success."

"I express my deepest condolences to the families and friends of those who were lost during these senseless acts of violence."

The shooting scene on Hosmer Street was within one block of a notorious massacre on Woolson Street that claimed four lives— including that of a 2 year-old boy— in September 2010.

The investigations into both shooting are ongoing, police said, and anyone with information is encouraged to call 1 (800) 494-TIPS or text the word ‘TIP’ to CRIME (27463).