Electricity, phone lines and then the water supply were cut off in a restive area of Syria that is a new center for protests against President Bashar al-Assad, and activists said 15 people died in the sixth day of sustained government attacks Thursday.

What started as street demonstrations calling for reforms has evolved into demands for Assad’s ouster in the face of a violent crackdown, especially in Syria’s south and agricultural center, where the challenge to his family’s 40-year-rule is seen as strongest. In the city of Rastan on Thursday, a resident who fled said troops swept through making arrests. He was reached by telephone and spoke on condition of anonymity for fear of reprisals.

Details coming out of Syria are sketchy because the government has severely restricted the media and expelled foreign reporters, making it nearly impossible to independently verify accounts coming out of the country.

But the resident said troops pounded the area that has been largely cut off from outside contact for six days with artillery and gunfire, bombing the town’s water supply as well as a mosque and a sports complex. Thursday’s deaths bring the total killed in Rastan and nearby Talbiseh to 72 since the onslaught began.

The Syrian government on Wednesday and Thursday freed hundreds of political prisoners in an amnesty and the president set up a committee for national dialogue in an effort to end the 10-week uprising, but concessions that would have been unimaginable only months ago were flatly rejected by protesters.