<span style="color: #222222;">A woman blew herself up in the centre of Tunisia's capital, Tunis on Monday. </span><br />'' <br />'' <span style="color: #222222;">According to state radio and news agency Reuters, the explosion took place on the Habib Bourguiba avenue which runs through the middle of the city.</span><br />'' <br />'' <span style="color: #222222;">Witnesses say the bomb detonated close to a number of police officers. </span><br />'' <br />'' <span style="color: #222222;">Several ambulances were already on the scene.</span><br />