At least 15 Taliban rebels were killed in two operations by Afghan and international forces in southern Afghanistan, officials said Monday. Afghan and NATO-led International Security Assistance Force (ISAF) troops killed 13 militants and wounded another 17 Sunday night after a police checkpoint came under attack, resulting in the death of three police officers, Kandahar provincial Police Chief Syed Agha Saqib said. The incident occurred in the Zherai district, where the forces were conducting an operation to rid the area of insurgents. Separately, the Afghan Defense Ministry said in a statement that National Army troops gunned down two militants in the Sewri district of south-eastern Zabul province and seized arms, ammunition and a communications device from the slain fighters. More than 2,000 people, mostly insurgents, have been killed in violence this year, with heavy fighting taking place mainly in the southern and eastern regions of the country, according to a report of DPA.