Port-au-Prince, Haiti (CNN) Haiti's leader has accused eight men, including five Americans, of being "terrorists" on a mission to destabilize his government.

Prime Minister Jean-Henry Ceant told CNN that the eight, who were arrested on Sunday , are "mercenaries" seeking "to target the executive branch of the government." He did not offer any further information to support this allegation.

The claim comes as both Ceant and president Jovenel Moise face calls to resign by Haitians fed up with the country's economic woes. The country's capital, Port-au-Prince, has been rocked by two weeks of deadly protests, which began February 7.

What we know so far

The detainees include five Americans, two other foreigners, and one Haitian, said Haiti's Police Chief Michel-Ange Gédéon. They were detained after being stopped during a routine traffic check. Their cars had no license plates and they initially resisted offering identification, according to Haitian authorities.

The men have not been charged, but are currently being held for alleged possession of illegal weapons. They are expected to appear in court in Port-au-Prince this week.

Haitian police say their cache of weapons included six pistols, six automatic rifles, two drones, five ballistic vests, three satellite phones, a telescope and several license plates. Automatic weapons are not permitted in Haiti.

"Today there is an investigation to determine how they came to the country, what is the mission they have and for whom they are working?" Gédéon told CNN. "If everything is normal, okay. If something is wrong we will find out."

CNN was not permitted to speak to the men in detention.

The detainees' alleged weapons cache.

The detainees' alleged weapons cache.

The five Americans detained in Haiti

US consular services have visited the Americans in detention. The US State Department confirmed the detentions but declined to provide any further detail about their cases due to privacy concerns.

CNN is working to get in touch with the Americans' families and to confirm further details, including whether the men have legal representation.

The detainees were allegedly also found in posession of multiple license plates.

The State Department on Thursday issued a Level 4 "Do not travel" travel advisory for Haiti, citing "crime and civil unrest" and "widespread, violent, and unpredictable demonstrations in Port-au-Prince and elsewhere in Haiti."