Massive dust storm followed by showers in parts of Northern plains brought down the mercury by several notches on Saturday providing respite to people from blistering heat wave. In the east, at least three labourers were killed in lightning in Odisha's Ganjam district. While in the west, monsoon arrived in south Gujarat and several areas of the state were lashed by rains. Telangana also received showers after bearing the brunt of heat wave which claimed scores of lives in the state and also in neighbouring Andhra Pradesh. An abrupt change of weather was witnessed this afternoon as dust storm hit the national capital and neighbouring states affecting visibility. In Delhi, a policeman was injured in high velocity winds blowing at 84 kmph. Later, rains lashed the region and brought down the temperature which was reeling above 40 degree Celsius for the past several days. The capital recorded 4.8 mm rains. The maximum temperature settled at 39.7 degrees while the minimum was recorded 29.0 degrees. Haryana and Punjab were also hit by dust storm followed by light rains. According to Meteorological department in Chandigarh, the dust storm hit Gurgaon, Faridabad, Mahendergarh, Rohtak, Ambala and Panchkula in Haryana. In Punjab, Mohali, Ropar and Amritsar were among other places to be hit by dust storm. Power supply was disrupted for a while in Chandigarh after the dust storm. Later, the city received light rains providing relief to the residents from the hot weather conditions. MeT officials said that the current change in weather was caused by an Upper Air Cyclonic Circulation which was active over west Uttar Pradesh and adjoining Haryana and Uttarakhand.