MINNEAPOLIS - Police are investigating two separate overnight stabbings that left two people critically injured.

According to Minneapolis police, the first stabbing happened on the Midtown Greenway beneath the Bloomington Avenue overpass in south Minneapolis.

Police say someone discovered the stabbing victim around midnight Sunday and called 911.

The victim was identified as John Paul Dale, 46, according to the police report. Dale’s brother tells KARE 11 he got the call about the stabbing around 12:45 a.m. and drove from Buffalo to check on his brother at HCMC.

"He was stabbed four times -- once in the chest and three times in the back,” said Marcus Dale, the victim’s older brother. “The one time in the chest pierced the heart."

Marcus says his brother has stabilized but is still in critical condition at the hospital.

He says Dale was homeless, involved in drugs, and living under the overpass where he was stabbed. He told KARE 11 Dale has been arrested several times and just got out of prison in June.

"I had him living here (in Buffalo) with me for a while until he got into too much trouble and violence and stuff like that,” said Marcus of his efforts to help his little brother. “Now my landlord won't allow him to live here."

Police say they arrested two 18-year-old men in connection with Dale’s stabbing. They’re in custody on probable cause of second degree assault.

The other stabbing happened shortly after 3 a.m. Sunday at 29th Avenue NE and Central Avenue in Northeast Minneapolis.

Officers say a victim was stabbed in the stomach during a robbery. No arrests have been made.

Police say both victims in the separate stabbings suffered critical injuries.

Police say the stabbings are not connected.

Officers say they are reviewing police camera video.