MANAMA, Bahrain — Thousands of jubilant protesters surged back into the symbolic heart of Bahrain on Saturday as the government withdrew its security forces, calling for calm after days of violent crackdowns.

It was a remarkable turn after a week of protests that had shifted by the hour between joy and fear, euphoric surges of people power followed by bloody military crackdowns, as the monarchy struggled to calibrate a response to an uprising whose counterparts have toppled other governments in the region.

“All Bahrain is happy today,” said Jasim al-Haiki, 24, as he cheered the crowds in the central Pearl Square, aflutter with Bahraini flags. “These are Bahrainis. They do what they say they will do!”

The shift in this tiny Persian Gulf nation, a strategic American ally, was at least a temporary victory for the Shiite protesters, who had rejected a call to negotiate from Bahrain’s Sunni monarch until the authorities pulled the military off the streets.