 However, increasing activity by Shi'a militants in Pakistan strained relations further.This was followed by the Taliban's capture of the city of Mazar-i-Sharif in 1998, in which thousands of Shi'a Muslims were massacred, according to Amnesty International.The most serious breach in relations came in 1998, after Iran accused the Taliban government's forces of taking 11 Iranian diplomats, 35 Iranian truck drivers and an Iranian journalist hostage, and later executing all of them.