A fire truck with its blinking lights was parked atop St. Paul's Earl Street Bridge on Friday morning. But instead of battling a blaze, the crew was hosing down the pavement to wash away blood.

The grisly scene was the cleanup from the night before, when 24-year-old Emmett L. Wilson-Shaw became the latest victim of gun violence in a deadly week in the Twin Cities.

In a span of just three days, five people were shot and killed in St. Paul and Minneapolis. As of Friday afternoon, police had made no arrests in any of the cases as they scrambled to figure out who fired the fatal shots and why.

Authorities have said in each of the incidents that the public is not at risk — including one Wednesday night in which a man was shot at a vigil honoring a woman three years after she had been killed near the same spot by an alleged gang member.

"There's too many killings every day, too many bodies getting dropped," said a St. Paul man who heard the gunshots from the Earl Street Bridge on Thursday from his home nearby. The man did not identify himself Friday out of fear for his safety.

As police investigate the motives behind the killings, officers on both sides of the river Friday said they are taking steps to address the spike in gun violence.

St. Paul police are reassigning some officers from specialty units to cover "hot spots," including on the East Side, where two shootings took place just blocks apart within 24 hours of each other, police spokesman Sgt. Mike Ernster said.

Ernster declined to identify the locations and number of officers to be allocated, but said, "The public will notice an increase in officer presence as we deal with these issues."

The killings this week were the eighth and ninth in St. Paul this year. In 2014, a total of 11 homicides were reported.

While most of the slayings earlier this year in St. Paul centered on domestic disputes, the motives of the four most recent shootings — which have spanned the past three weeks — are under investigation.

Minneapolis is also stepping up patrols in troubled areas. Homicides in Minneapolis have reached levels not seen in nearly 10 years, mirroring a similar increase in other large U.S. cities. Overall, violent crime across the city is up more than 5 percent from this time last year.

A police spokesman on Friday said the department would hold a news conference Tuesday to address the outburst of violence.

East Side shooting

In Thursday's bridge incident on St. Paul's East Side, police responded to a report of shots fired around 7 p.m. and found a wounded man who was later pronounced dead. The man, identified as Wilson-Shaw, of St. Paul, had been walking to his mother's house with his cousins when he was shot, said Franni Rock, a close friend of Wilson-Shaw's sister.

On Friday, Rock tied balloons to the bridge's fence in honor of Wilson-Shaw, whom she described as a "down-to-earth" person. His death was especially hard for loved ones, she said, since his brother, Josh, was shot and killed seven years ago not far from where Wilson-Shaw was slain, Rock said.

Ernster said investigators do not believe Wilson-Shaw's death was related to the killing a night earlier of Synika G. James, who was shot while attending a vigil near Cypress Street and E. Reaney Avenue.

Minneapolis gang dispute

In Minneapolis, some of the recent violence has been tied to a bitter dispute within the Black P. Stones gang, community leaders say. The feud has been behind several recent shootings, they say.

But it is not clear whether gang violence was responsible for the killing Wednesday of 19-year-old Elija Larkin as he got off a bus outside a north Minneapolis church.

Police don't believe Larkin's killing is connected to a drive-by shooting the following day near Farview Park of a man who was sitting in a car with three other people, including a boy younger than 1. The infant was unharmed, but the man died Friday, police said.

The slaying of a 28-year-old woman earlier in the week in south Minneapolis also remains unsolved.

On Friday, KG Wilson, a longtime peace activist, arrived at the scene of the drive-by shooting across the street from Farview Park, as he has dozens of times before. He and a small group of volunteers held signs urging motorists driving by to help end the rampant violence.

The responsibility for ending the violence, Wilson said, falls as much on neighbors as it does on the police.

"Now, the outcome of it is there's been a shooting where a baby could have been killed."