Activists say Syrian troops have stormed parts of the eastern city of Deir el-Zour and explosions can be heard throughout the area. An activist in the city tells The Associated Press the military launched a pre-dawn raid on Sunday on the city,attacking it from four sides,and so far,taking control of eight neighborhoods. On Saturday,Syrian forces tightened a siege on the city of Hama,the main center of the nearly five-month-old uprising against President Bashar Assad's regime. The activist said the military raid on Deir el-Zour began at 4 am on Sunday. The activist spoke on the condition of anonymity,fearing reprisals. The Local Coordination Committees,an activist group tracking the uprising,confirmed parts of the city were taken over by troops. There was no immediate word on casualties.