KAMPALA, Uganda (AP) — Ugandan authorities said Tuesday that they have detained dozens of foreigners in a crackdown on illegal migration that the internal affairs ministry suggested was linked to human traffickers and cyberscam operations.

At least 231 people have been detained since Monday in operations that targeted a group of Nigerians living in the country’s north, as well as another group of foreigners living together in a closed compound in Kampala, the capital.

The second group included people from Pakistan, India, Bangladesh, Ghana, Myanmar, Ethiopia, Sri Lanka, Cambodia and Malaysia, all of whom were staying in “a highly restricted, self-contained apartment complex equipped with its own restaurant and internal facilities designed to restrict movement,” according to the Ministry of Internal Affairs. Thirty-six of the 169 people found in the compound were women.

Authorities say they acted on intelligence showing large groups of foreigners living or working in Uganda without the necessary papers to do so. Many didn’t have passports, the ministry said in a statement.

“Some individuals have claimed they were trafficked into Uganda with promises of employment,” the statement said. “Others were engaged in cyber-scamming activities. A few were found in possession of materials suggesting involvement in other criminal activities.”

Those found to have broken the law face criminal prosecution, it said.

Simon Peter Mundeyi, a spokesman for the Ministry of Internal Affairs, told The Associated Press that there were three categories of foreigners now held for questioning in two places: suspected victims of trafficking, alleged perpetrators, and those who simply overstayed their visas but did not engage in criminal activities.

The trafficking victims and the overstayers would be helped to leave Uganda after buying their own tickets, he said, while those authorities identify as suspected ringleaders of trafficking will be charged and could eventually face deportation.

Uganda has a reputation for welcoming foreigners, hosting hundreds of thousands of refugees fleeing violent conflict in neighboring countries such as Congo, Burundi and South Sudan. For short visits, entry visas are not required for people from many countries in Africa and elsewhere.