The tourists are struck in the town of Ulgii in the west of Mongolia after it was placed under quarantine because of the deaths of a married couple from the plague, Russian daily The Siberian Times reported.
The couple who lived in the area contracted the illness after eating raw marmot meat, the paper reported.
Some 158 tourists from countries including Sweden, South Korea, Germany and Russia are now reportedly waiting for the all-clear to be given so that they can leave the town.
Around ten Swiss tourists are affected by the current travel ban, the Swiss Federal Department of Foreign Affairs confirmed to Swiss daily Le Matin.
A spokesperson for the ministry said that “according to ministry information, their [the Swiss tourists] health is not in danger, and they will be able to leave the region soon”.
Bubonic plague can kill quickly but it is treatable with antibiotics, so early diagnosis is critical.
From 2010 to 2015, there were 3248 cases reported worldwide, including 584 deaths, according to the World Health Organization.