A 30-year-old Syrian suspect turned himself in to police at 1am at Midnight Emotions, described by local media as a “sex club”, in the town of Zizers.
The alleged gun-toting culprit barricaded himself in the club with two women, aged 23 and 48, and a man on late Thursday afternoon, police said.
Officers were called to the scene after receiving a report at 4.25pm of two shots being fired over what investigators believe was a “relationship” dispute.
A massive police contingent surrounded the club and sealed off a security perimeter around the club for eight hours.
A trained police negotiator and an acquaintance of the alleged offender talked to the man for a lengthy period, police said in a report.
One of the hostages, the 48-year-old man was released during the evening, according to the report.
After a period of “tough negotiations” the suspect threw his gun out of a window and came out with his hands raised, cantonal police said.
The man was arrested and the two women hostages were freed unharmed, police said.
An investigation continues into the case that involved city police from Chur and forces from the cantons of Glarus, Zurich and Liechtenstein, as well as emergency services from the region.
The road between Zizers and Trimmis was closed during the incident but the A13 motorway was unaffected, police said.
Midnight Emotions advertises itself on the internet as an "erotic club" and lounge in the mountain town of 3,000 people, with services offered by 14 "girls".