At least 97 people have been killed and dozens wounded in a massive suicide truck bomb blast at a petrol station south of Iraq's capital Baghdad, according to medical sources.
The target of Thursday’s attack near the town of Hilla appeared to be Shia Muslim pilgrims returning from the annual Arbaeen pilgrimage in the holy city of Karbala.
Al Jazeera's Hoda Abdel-Hamid said, reporting from Erbil, said the attack involved a rigged petrol tanker which was parked near a petrol station that also has a restaurant popular with travellers on its premises.
"When the gas tanker blew up, it also torched several buses and minivans that were carrying the pilgrims," Abdel-Hamid said.
"The whole place was completely wrecked. It was a massive blast."
Our correspondent said that as of 19:00 GMT on Thursday the number of those killed in the attack at 97, rising from a previous death toll of 80. Earlier, security sources had said they expected casualty figures to increase in the coming hours.
"It is believed that among them are not only Iraqis, but some Iranians too, while some unconfirmed reports also say that there could be some Bahrainis among the victims."
"With today's attack, ISIL is sending the message that it can still cause and inflict a lot of pain," Abdel-Hamid said.
Videos circulating on social media showed debris scattered over a large area along the main highway linking Baghdad to the main southern port city of Basra.
"There are completely charred corpses at the scene," said Falah al-Radhi, head of the provincial security committee, who added that at least 20 wounded were transferred to nearby hospitals.
The Joint Operations Command in Baghdad issued a statement saying the lorry was packed with 500 litres of ammonium nitrate, a chemical compound used in many explosive devices.
ISIL has intensified attacks over the past month in areas out of its control in efforts to weaken a large-scale military offensive launched last month to retake Mosul, the last major city under its control in Iraq.
The latest attack "highlights just how difficult it is to guarantee any kind of security in certain areas of Iraq," Al Jazeera's Charles Stratford, reporting from Dohuk in northern Iraq, said.
"Despite of evidence of ISIL getting hit very hard, they still seem to be able to attack when and where they want in certain parts of the country."
The International Organization for Migration said onThursday that around 76,000 people had been displaced since the start of the Mosul offensive on October 17.
The group said that about 7,000 people had already returned to their homes, leaving roughly 69,000 still displaced, most of them in camps.