A Filipino woman was found dead on Monday outside a train station in Mandaluyong City, the Philippines, from what police suspect was a stabbing.

On Monday afternoon at Boni Station, the woman reportedly had an argument with a male beggar before she was found dead. The victim, whose identity is still not known, was also a beggar, Philippine Daily Inquirer reported.

Train station personnel initially thought the woman had suffered a heart attack and called for an ambulance. However, a stab wound was found on her lower chest and her clothes were bloodstained. When the ambulance arrived, the woman had no heartbeat.

Police Senior Master Sergeant Gregorio Akbay from the Mandaluyong police station said the woman had been standing and drinking juice when the suspect arrived and suddenly took out a weapon that looked like an ice pick or a screwdriver. The two had an argument and the suspect stabbed the woman.

Police are reviewing security camera footage in a bid to identify the suspect. Authorities are conducting a follow-up operation to locate the male beggar.