JERUSALEM — Israel is notifying thousands of Africans who entered the country illegally that they have three months to leave or face incarceration.

The Population and Immigration Authority called this week on migrants from Sudan and Eritrea to leave “to their country or to a third country,” meaning Rwanda or Uganda. Those who leave by the end of March will be given $3,500, along with airfare and other incentives.

The Hotline for Migrant Workers, an advocacy group, condemned the move Tuesday, saying expulsions “put the refugees’ lives in danger.”

Thousands of Africans entered Israel before it erected a fence along its border with Egypt. Many say they fled conflict and persecution and seek refugee status. Israel calls them “infiltrators” and says they are mostly economic migrants whose numbers threaten its Jewish character.