On 7 May 1999, between approximately 11:30 and 11:40, fighter jets of the Royal Netherlands Air Force dropped two containers of cluster bombs over the city of Niš. The intended target was reported to be Niš Airport, located at the edge of the city, but the munitions impacted near the city center, at least 3 km from the airport. Scattered by wind after release, the bomblets fell in three separate locations in the central part of the city: the Pathology building adjacent to the Medical Center of Niš in the south, the area near the "Banovina" building including the main market, bus station and Niš Fortress, and the parking area of "Niš Express" near the Nišava River.
According to a Human Rights Watch report, 14 civilians were killed in the attack and another 28 were injured. A separate report by Večernje novosti put the death toll at 16 civilians. The high casualty figures were attributed to the timing of the strike, which occurred in the middle of the day when civilians were congregating in the streets and, especially, at the market, where the greatest number of deaths occurred.
A second bombing took place on 12 May 1999, striking the eastern part of the city, an area known as Duvanište, which is more than 7 km from the airport. This second attack resulted in 11 civilian injuries, many of them amputations. The most recent fatality connected to this bombing occurred in the year 2000, when an unexploded bomb from the attack detonated.
In the aftermath, the Royal Netherlands Air Force stopped using cluster bombs for the remainder of the NATO campaign, although other NATO members continued to use them. A report by Amnesty International stated that NATO gave no explanation for why cluster munitions were deployed against targets located so close to a civilian population, and concluded that NATO had violated Article 51(4) and (5) of Protocol I to the Geneva Conventions, which prohibit indiscriminate attacks affecting civilians.
As of 2009, hundreds of unexploded cluster munitions were reported to still be present in the Serbian countryside, despite efforts by the Serbian government to clear affected sites of such ordnance.