Gurugram, Nov. 12 -- Two 12-year-old girls drowned in an artificial pond at the golf course of an under-construction residential society in Gurugram's Sector 71 on Tuesday, after they and two other girls from a nearby village entered the premises through a gap in the fencing, police said on Wednesday. The incident took place between 12.30pm and 12.45pm at the golf course where the girls - identified as Sajan Kumari and Naina - lived in a rural settlement adjoining the site, according to Gurugram police officials. Police said four girls from the village had taken an unpaved road to reach the rear of the golf course and entered through a gap in the fence. Sajan had gone out with her sister Nandani while their father was away at work, a police officer said. A senior police officer said the premises were fenced and also had a boundary wall. However, a tree at the rear had left a small gap in the fencing, through which the girls entered the site. No guard was present in the golf course's guard room at the time of the incident, he added. According to the officer, Sajan was the first to slip into the deeper part of the pond and drown. Naina tried to rescue her but also slipped into the water. "The artificial pond had a large sheet of black plastic at its base, which prevented the girls from getting a proper grip to get back to the edge," the officer said. The golf course had one large pond filled with water and at least 10 smaller ponds, which were dry, police said. The two other girls ran home to alert their families. The families called the police control room around 1pm, following which emergency response teams reached the spot. Police personnel pulled the girls out of the pond and administered cardiopulmonary resuscitation (CPR), but they remained unresponsive. They were taken to the civil hospital in Sector 10A, where doctors declared them dead on arrival. One girl's father works as an autorickshaw driver, while the other is employed with a private firm. Kuldeep Kumar, assistant commissioner of police (Badshahpur), said an FIR had been registered against unidentified persons at Badshahpur police station on Tuesday. The case has been registered under sections 106 (causing death by negligence) and 3(5) (common intention) of the BNS....