BAMAKO, Mali — Isolated for centuries by the harsh desert that surrounds it, Timbuktu now finds itself even more cut off from the rest of the world.

Rebels who captured the city in northern Mali in April have imposed a form of hard-edged Islamic rule, prompting many residents to flee in fear and changing the face of what had been a tolerant and easygoing destination that drew tourists from around the world.

Women are now forced to wear full, face-covering veils. Music is banned from the radio. Cigarettes are snatched from the mouths of pedestrians. And the look of the ancient mud-brick town is changing. A centuries-old monument, the shrine of a 15th-century saint, has been defaced; bars have been demolished; and black flags have been hung around town to honor Ansar Dine, or Defenders of the Faith, the radical Islamist movement that emerged from the desert and turned life upside down.

“There is no liberty,” said Abdoulaye Ahmed, a tailor who fled Timbuktu and came to Mali’s capital last week. He added that the Islamist rebels “are constantly circulating with their guns. This is scaring people. The town is sinister.”