2013. According to Reuters, hundreds of fighters had gone to Syria to fight alongside their "Mujahedeen friends". Media reported the visit and setup of a TTP base in Syria to assess "the needs of the jihad". At least 12 experts in information technology and warfare were sent to Syria in the last two months to aid the Mujahideen. The Pakistani government has not commented on the allegations. North Waziristan offensive On 19 December 2013, the army launched a major offensive in the Mir Ali region of North Waziristan following a suicide bomb attack on a checkpoint in the area the previous day. Artillery and helicopter gunships were used in the operation. By 23 December, more than 30 militants and up to 70 civilians allegedly were killed. Tehreek-e-Taliban Pakistan infighting In March 2014 rival factions fought for control of Tehreek-e-Taliban Pakistan. Commander Khan Said Sajna and followers of the late TTP leader Hakimullah Mehsud now under command of Maulana Fazlullah clashed in Shaktoi area of South Waziristan and later in the same area in early April 2014. This began a bloody struggle for control of the organization. After several minor skirmishes another major attack took place in the Shawal area of the troubled North Waziristan district on 6 May 2014. Operation Zarb-e-Azb In response to the IMU's Jinnah Airport attack on 8 June 2014, the Pakistani military launched an operation on 15 June 2014 against the militants in North Waziristan including the Tehrik-i-Taliban Pakistan (TTP), Al-Qaeda, East Turkestan Islamic Movement (ETIM), the Islamic Movement of Uzbekistan (IMU) and the Haqqani network. Up to 30,000 soldiers were involved in the operation. It had been described as a "comprehensive operation" that aimed to flush out foreign and local militants hiding in North Waziristan. By 2014, casualty rates in the country as a whole dropped by 40% as compared to 2011–13, with even greater drops noted in Khyber Pakhtunkhwa, despite the province being the site of a large massacre of school children by Tehrik-i-Taliban terrorists in December 2014. By December 2015, some 3,400 Pakistani Taliban and their allied fighters were killed during the first 18 months of the operation, according to the ISPR. By June 2016, a total of 3,500 militants were killed, including 900 terrorists belonging to Lashkar-e-Islam, according to the Director General ISPR. 490 soldiers were also killed in the two-year operation. A kinetic military action was conducted and Shawal valley was