On Tuesday, Salvadoran President Nayib Bukele said via Twitter that the move stemmed from Salvadorans flying into Guatemala from overseas in an effort to avoid government quarantines and then traveling over land to El Salvador.
Bukele also said that foreigners from several countries impacted by the virus -- Spain, Italy, France, Germany, China and South Korea -- will not be admitted into the country.
Salvadorans coming from those countries will be subject to a 30-day quarantine.
Around 90 people have been placed in quarantine after arriving from the restricted countries. None have tested positive for the illness.
Costa Rica recorded the first coronavirus case in Central America last week.
The Associated Press contributed to this report.