A 39-year-old man is in critical condition after being stabbed on a Q train at the Church Avenue station in Flatbush early Friday morning. Police say the stabbing happened just before 1 a.m. while the train was stopped at the station. Investigators say the man got into an argument with another person before he was stabbed. EMS rushed him to Kings County Hospital, where he remains in critical condition. No arrests have been made, and investigators are still trying to find the person responsible. The stabbing comes after several violent incidents across Brooklyn this week. On Wednesday, Jaymel Dillahunt, 38, died after being stabbed near the Van Siclen Avenue station in Cypress Hills. Later that same night, 34-year-old Isaiah Freeman was stabbed to death outside a shopping plaza in Canarsie. Then on Thursday, David Martinez, 36, was killed outside a grocery store in Sunset Park, while another man suffered cuts to his face. The latest incident on the train has some riders concerned. "That’s a shame, that’s a tragedy," Flatbush resident Leon Smalls said. "There needs to be cops here on this train station." NYPD crime data shows there have been 11 reported transit crimes in the precinct that includes the Church Avenue station so far this year. At the same point last year, there were just three. The investigation remains ongoing.