A tota of 560 illegal immigrants, mainly from the Great Lakes region, entered Mwanza region between January 2011 and May, this year.
Mwanza Regional Immigration Officer Omary Mellem said yesterday that his region has been facing an influx of illegal immigrants because of its attractive geographical position.
The region borders Kenya and Uganda and is also near some countries of the Great Lakes regions which are facing civil strife.
Mellem said last year a total of 354 illegal immigrants were arrested, while 206 others were arrested between January and May this year.
He said it was likely that the number of illegal immigrants entering Mwanza from neighbouring countries would increase this year.
Mellem said a total of 412 illegal immigrants were repatriated to their respective countries, while 20 others were arraigned, nine of whom were given custodial sentences and two were sentenced to pay fine while two were acquitted.
A total of 36 immigrants were naturalized between January and May, this year, while 54 others have their cases still pending.
He said many illegal immigrants cross into Mwanza because of fishing, agriculture and pastoralism.