"The Turkish army shelled a district of the Nusaybin city in southern Turkey using munitions which are likely to contain the banned substance of phosphorus," the source said.
Nusaybin is located in the Mardin province, where two Turkish servicemen were killed during a raid against the Kurdistan Workers’ Party (PKK), outlawed in the country, earlier in the day.
White phosphorus munitions are used in smoke and incendiary munitions. White phosphorus is not specifically banned, but the 1983 UN Convention on Certain Conventional Weapons bans the use of incendiary weapons in indiscriminate attacks against civilians.
The Kurds comprise ancient tribal groups, which are currently living in parts of Turkey, Iran, Iraq and Syria. In Turkey, Kurds represent the largest ethnic minority, and are striving to create their own independent state.