Department spokesperson Ally Mtanda told The Guardian in a telephone interview yesterday that Kigoma region led the way with 388 illegal immigrants, mostly from the Democratic Republic of Congo (DRC), Burundi and Rwanda.
He named other regions with significant illegal immigrant figures as Kagera (347), Dar es Salaam (198), Tabora (163), Mara (85), Shinyanga (84), Njombe (31), and Morogoro (28).
“There are increasing cases of illegal immigrants in the country with the majority coming from neighbouring, war-torn nations,” said Mtanda.
He explained that the list includes 858 Somalis and Ethiopians, who he said normally enter the country through clandestine border points in Arusha, Kilimanjaro and Tanga regions on their way to South Africa, lured by promises of jobs and greener pastures.
According to Mtanda, immigration department officers were during the period stationed at key centres including within bus stations, along highways, guest houses, and big farms.
Their functions included regular inspections of all vehicles, especially upcountry passenger buses, he explained.
After being arraigned and formally convicted in court for entering the country illegally, some of those arrested paid fines and were then allowed to go free, others were jailed, and others were deported to their countries of origin, he added.
Eleven vehicles were confiscated by immigration department officers for being used to facilitate the movements of the illegal immigrants within the country, Mtanda said.
He called on members of the public not to hesitate about reporting any people they suspect of being illegal immigrants to the relevant authorities.
In early 2016, immigration department officials launched an operation to deport hundreds of foreign nationals found to have entered the country illegally, or working without permits within the country.
Former deputy commissioner of immigration Wilson Bambaganya said a total of 4,792 foreigners who had no permits were arrested between January and February 2016 alone.
Out of them, 557 were asylum seekers fleeing unrest in their own countries, according to Bambaganya.
He expressed official concerns about the rising numbers of illegal immigrants into the country, mostly believed to be coming from known hotspots in the African continent and the Middle East.