French and Malian troops have fought running battles with Islamist rebels in the centre of Gao, the main city in northern Mali. Gunfire echoed through the streets and mud-brick houses of the city as the rebels engaged the Malian army in a surprised attack. Tomas Fessy who is in Gao witnessed some of the fighting.There is heavy gunfire coming from different parts of town. A Malian soldier who is holding the position where we are told me that some of Islamist fighters are driving by motorbikes. People are now barricaded into their houses as the situation remains unclear.__________________________________________________________________________________________________________________________.