At least 75 people have died after a petrol pipeline explosion and fire in Kenya's capital, Nairobi, police say. The blast took place in the city's Lunga Lunga industrial area, and police and troops cordoned off the area as firefighters battled fierce flames in the surrounding shanty town. The pipeline runs through the densely populated Sinai slum area between Nairobi's city centre and the airport. More than 110 people have been taken to hospital, officials said. Reports suggest Monday's blast may have been sparked by a cigarette butt being thrown into an open sewer that was filling with fuel. The fuel leaked into a storm drain from the Nairobi-Mombasa pipeline, the Kenya Pipeline Company said in a statement. Residents said the spill had prompted many people to rush and collect leaking fuel. Parts of bodies littered the remains of burning shacks for some 300m (1,000ft) around the site of the blast, locals said. Some of the shacks were built on top of the pipeline, residents say. 'Jumped into river' "Then there was a loud bang, a big explosion, and smoke and fire burst up high," resident Joseph Mwego told Agence France-Presse. Bodies were also seen floating in a nearby river, into which burns victims had reportedly leapt after catching fire. TV images showed survivors staggering around in a daze, with skin peeling off their faces and arms, and schoolchildren running in all directions. One of the survivors, Jane Mumbua, said many people were close to the pipeline at the time of the blast. "I just heard a big blast and that's when I started seeing people on fire. All around me there was fire," she said. A Red Cross official, Pamela Indiaka, said at least 75 bodies had been recovered. Some reports put the toll at more than 100 dead. Kenyan Prime Minister Raila Odinga, who visited the scene of the blast, described what he had seen as "shocking" and "terrible". "This, I think, is one of the worst disasters that has happened here in this country in the oil sector," he said. "I think that by the end of the day we'll have a clearer picture of the extent of damage." Richard Leresian, the head of the Kenyatta National Hospital, said 112 people had been brought to the hospital, most of them with more than 30 degree burns. None of those brought in had died, he said. There have been other deaths in Kenya involving people collecting leaking fuel. More than 100 people died in Molo, western Kenya, in 2009 after a fire on an overturned tanker.