Libyan forces have been pounding Islamic State (IS/Daesh) targets with artillery shells as they edge further into the centre of Sirte seeking to recapture the city from the militants. Forces aligned with Libya's United Nations-backed government in Tripoli advanced rapidly on the militant group's Libyan stronghold in May, but they have faced resistance from snipers, suicide bombers and mines.

Reuters photographer Goran Tomasevic has been accompanying the government-backed forces as they advance towards the centre of Sirte. He says: "When everyone shouts 'Allahu Akbar' (God is Great) I know that a tank or a cannon will fire."

"It is very difficult for me to communicate with the fighters because I don't speak Arabic and most of them they don't speak English. Most of the communication is by gesturing or shouting when the accurate IS fighters start firing," the photographer says.

Tomasevic says capturing the battle requires "more and less constant running and shooting pictures with small breaks between. If one group of fighters slows down I would go to check another group."

After Islamic State took control of Sirte – Gaddafi's hometown - last year, the militant group turned the city into its North African stronghold, extending its control along about 250km (155 miles) of Libya's coastline. Officials say a few hundred militants are left in the city, including highly trained snipers who have inflicted heavy casualties on the Misrata-led forces, some of whom come to the battlefront in flip-flops or jeans.

The latest surge by the brigade came on Thursday (24 July). They claimed they took grounds on several fronts, but at a cost of at least 25 dead and 200 wounded fighters. "After sending the pictures I went straight to bed. All day running in the sun made me sick," said Tomasevic. Like the fighters, he has to deal with temperatures well over 30 Celsius (86 Fahrenheit), though food and water are delivered into the thick of the battle.

"It was challenging to shoot the pictures, I pushed very hard and I did not get what I really want, but I am still happy because I am covering such important story," he says. "My goal is to cover the final battle for Sirte."

Sirte has been controlled by Islamic State since February 2015, becoming its most important base outside Syria and Iraq, and its loss would be a major setback for the group. The city is on the Mediterranean, about halfway between Tripoli and Benghazi.