A suicide bomb attack at an Iraqi gas station has killed at least 100 people, most of them Shia tourists from Iran, local authorities said.
Islamic State, which views Shias as apostates, has claimed responsibility for the attack in Iraq's hill city of Hilla, which is about 100 kilometres from Baghdad.
The victims were on their way back to Iran from the Iraqi Shi'ite holy city of Kerbala, where they had commemorated Arbaeen, the 40th day of mourning for the killing of Imam Hussein, a grandson of the Prophet Mohammad, in the 7th century AD, the medical sources said.
The attack took place at a gas station that is popular among travellers.
Five pilgrim buses were torched by the force of the blast from the explosives-laden truck, a police official said.
Islamic State has escalated attacks in areas that have gone out of their control, in a bid to slow down and weaken the Mosul offensive.
The attack on Shia tourists comes at a time when Shia militias have been at the forefront in the fight against IS in Iraq.
Iran's Foreign Ministry condemned the attack without giving a casualties toll. Tehran will continue to support Iraq's ''relentless fight against terrorism," ministry spokesman Bahram Qasemi was quoted as saying by Tasnim news agency.