Tens of thousands of Haitians could be forced to leave the neighbouring Dominican Republic after a court ruled they may not be eligible for citizenship - even if they were born in the country.
Hundreds have already returned to Haiti amid nationalist violence in their adopted homeland.
In September, a Dominican court ruled that citizenship would not necessarily be granted to anyone born to undocumented migrants after 1929.
The ruling has led Caribbean leaders to defer an application from the Dominican Republic for membership in CARICOM, the region's largest trade and cooperation bloc.
Haitian advocate groups say descendants of migrants have been forcibly deported since the ruling, a claim strenuously denied by Dominican officials.
Fiordaliza Matos was born in the Dominican Republic, 21 years ago.
Her father is Dominican, her mother Haitian. As such, she has does not have citizenship and is now at risk of being deported to Haiti - a country she's never been to.
"My life, people, adolescence, church - all of it is here," she told Al Jazeera's Cath Turner.
"So despite them saying I'm from there, being over there would be like a different world."
Jose Hipolito Martinez, the general supervisor of immigration services, said: "The Dominican immigration authorities haven't launched any campaign of deportation, of any kind.
"The law is clear, if a foreigner got into the country in an illegal way, or you're somehow found in an illegal condition, we will deport them."
The two countries on either side of this border have a volatile history.
But last weekend, when violence broke out in a tiny village in the southwest of the Dominican Republic, the level of animosity went to a whole new level.
According to Dominicans in this remote area, two Haitian men robbed and murdered an elderly Dominican couple - and subsequently disappeared.
In retaliation, an angry group of Dominicans killed two other Haitian men.
Dominican police say they have escorted about 600 Haitians across the border, at the Haitians' request.