The Afghan Taliban is responsible for militant attacks inside Pakistan

From the articlePakistan Says It Killed 28 Militants, Afghan Taliban and UN Report Three Civilian DeathsAlso in Pakistan says strikes in Afghanistan killed '28 terrorists', Pakistan says airstrikes in Afghanistan kill 28 militants; Kabul reports 3 civilians killed, Pakistan says it killed 28 militants, Afghan Taliban and UN report three civilian deaths | Reuters, Afghanistan says three killed in Pakistani air attacks