Fire has engulfed an arms factory in the Sudanese capital, Khartoum, following an explosion.Khartoum governor Abdul Rahman al-Khidir told state media that no-one had died but that some people had suffered smoke inhalation.The reason for the blast at the Yarmouk industrial complex in the south of the city is not yet clear.Flames also spread to nearby buildings causing panic among local residents, local media said."There was a very loud explosion and you can see now a huge fire," one resident told Reuters news agency.'Flashes of white light'Armed forces spokesman Col Al-Sawarmi Khalid said the explosion set light to surrounding grass and trees sending flames over a wide area, state news agency Suna reported.He said civil defence forces had contained the fire."Investigations are under way to determine the causes of the explosion as well as assessing human and material loss," he said.Witnesses reported seeing two or three fires with dense smoke and intermittent flashes of white light.Mr Khidir, governor of Khartoum state, told local TV that the explosion had occurred at midnight."There are losses in the building and the authorities are investigating the cause. A preliminary investigation says the explosion happened in a store room," he said.Mr Khidir said some people had been taken to hospitals suffering smoke inhalation but otherwise there were no casualties.In 1998, the US launched a missile attack on a pharmaceutical plant in Khartoum, alleging that it was making materials for chemical weapons.Sudan denied the allegation, insisting that the US had attacked a factory that manufactured anti-malaria medicines and veterinary products in defiance of international laws.