KABUL: A huge blast was heard in the Afghan capital Saturday as a US military official arrived for meetings to explain the sacking of the US commander of foreign forces in the country, witnesses told AFP. The blast took place in the centre of the city, at 9:55 am, the witnesses said. A spokesman for the interior ministry, Zemarai Bashery, said he had heard the blast, the cause of which was being investigated. It seemed to have taken place near the foreign ministry, he said.