In a week marked by xenophobic attacks in South Africa and strong backlash from even Tanzania's parliament, Dar es Salaam's Regional Commissioner Paul Makonda announced a plan to carry out door-to-door searches and registration of alleged immigrants in the country's commercial capital. They are being blamed for the spike in crime.
The residential registry will identify where each and every city resident lives and work.
Building on an existing system that requires all local representative to keep tabs on and report all "new" people moving into their locations, Mr Makonda's directive will see local community groups tasked with detecting "strangers" or "suspicious-looking people in their areas, and reporting them to the police or other law enforcement authorities for further action.
According to his office, there were 16,000 unidentified visitors in Dar es Salaam last year alone.
He further instructed ward, council and district leaders to work with immigration and national security officials to enforce his directive.
The issue of illegal immigrants has been a thorny one in Tanzania. Authorities say illegal aliens endanger the country's social and economic stability and pose a security risk.
Mr Makonda accused illegal aliens of misusing state resources and taking over jobs and education opportunities meant for Tanzanians.