Police in Philadelphia say a 2-year-old girl was fatally shot Sunday afternoon when a gunman opened fire into her home from outside, CBS Philadelphia reported. The fatal shooting came a day after an 11-month-old boy was shot four times and left in critical condition, the station reports. No arrests have been made in either case.

Sunday's shooting happened around 3:30 p.m. in a home in Philadelphia's Kensington section. Police say an unidentified gunman targeted the home, but it's not clear who was the exact target or why he opened fire. Nikolette Rivera was struck in the back of the head and died, the station reports. An officer on the scene told CBS Philadelphia the gunman wielded an AK-47-type weapon.

"No child should be murdered in their living room. It's just terrible," Acting Philadelphia Police Commissioner Christine Coulter told reporters at the scene.

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The child's 24-year-old mother was shot in the right side of the head and in the back, the station reports. She was reportedly in stable condition. A 33-year-old man doing renovation work was shot in the stomach and is in critical condition. Police said the mother had been "holding her daughter at the time of the shooting," the Philadelphia Inquirer reported.

Someone opened fire on a car shortly before the shooting about a half a mile away, and ballistic evidence found at both scenes was similar, Coulter said. No one was injured. Investigators are looking into whether the shootings are linked, Coulter said.

"It's heartbreaking. Any crime or anybody shot is a horrible thing, but when people indiscriminately shoot and kill babies or shoot babies, it's unexplainable," Coulter said. "I can't imagine someone thinking at any time to fire a gun, but to do it with the thought that there are or could be children involved, it breaks my heart."

Another shooting in Philadelphia over the weekend left an 11-month-old boy critically wounded as he rode in a car in the Hunting Park neighborhood, the station reports. The child was reportedly shot once in the head, once in the chest and twice in the buttocks.

Nikolette Rivera Family photo

Police said the boy's stepmother said she was driving with the infant in the car when she heard gunshots. The woman kept driving until she got home, and then realized that the child had been struck.

According to the Philadelphia Inquirer, Philadelphia police Capt. Nicholas Brown said the child is in "very, very, very critical condition" and may not survive. If he does, he is likely to be quadriplegic, Brown said.

The shootings come amid concern over increasing gun violence in Philadelphia officials have called a "public health crisis." Philadelphia has recorded 300 victims of homicide so far this year, according to police, more than 278 recorded at the same time year-to-date in 2018. Last year, Philadelphia saw 351 homicides -- more than the city had recorded in over a decade.

Philadelphia Mayor Jim Kenney released a statement Sunday night about the two shootings.

"I am outraged, disgusted, and heartbroken by the violence this weekend that claimed the life of an innocent 2-year-old and left another infant fighting for his life. My prayers are with their families and communities during this tragic time," Kenney said.

A $30,000 reward is being offered for information that leads to an arrest in either case, the paper reports. Anyone with information is asked to call police.