FOUR drug suspects were killed, while one was wounded in a series of gun attacks in separate parts in the southern part of Metro Manila on Monday. Honorato Navarro Jr., 54; Nadja Dumanin, 39 and Vincent Manaluz were killed by gunmen riding a motorcycle in two separate incidents in Las Piñas City. Navarro who has surrendered to the police as drug user was gunned down at past 4 p.m. in Barangay Daniel Fajardo. Couple Dumanin and Manaluz were shot dead by three armed men at their eatery in Barangay Talon Singko at about 6 p.m. The shooting also wounded their staff, Ester Doctolero, 37. Las Piñas police said the two were also drug surrenderers. In Taguig City, Julius Ceasar Buenaflor, 45, was shot dead by an unidentified man riding a motorcycle in Barangay Ususan at 6 p.m., while he was sitting on a bench along Tomasa Avenue. Buenaflor is a village councilman. Police said he was included in the drug watchlist. Meanwhile, Muntinlupa City police arrested Santiago Awit, 57, in a buy-bust in Barangay Bayanan at 10 a.m. on Monday.