About 630,000 counterfeit mobile phones have so far been disconnected in Tanzania, the telecom authority says.
A government ban on using fake phones came into force at midnight, causing communication difficulties for those who owned them.
Tanzania joined Cameroon, South Africa and Nigeria in efforts to boost security and health measures by disconnecting the phones.
About 3% of mobile phones in Tanzania are fake, official figures show.
The country has about 33 million mobile phone subscribers, out of an estimated population of 49 million people.
Some 1.2 million fake phones are expected to be disconnected, local media reports.
But overall, the ban has been welcomed and many are wondering if it will also lead to a crackdown on other counterfeit goods, he says.
The opposition Civic United Front (CUF) has said the ban “punishes” innocent Tanzanians for the government’s failure to prevent fake phones from entering the market.
Deputy Communication Minister Edwin Ngonyani said the shutdown would “strengthen efforts by the government to bring to book criminals who have been using fake handsets which cannot be traced”.
Counterfeit handsets lack authentic International Mobile Equipment Identity (IMEI) numbers that are crucial to identifying and tracking mobile phones, making it easier for criminals and militant Islamists to escape detection.
The Tanzania Communication and Regulatory Authority said the switch-off was also meant to protect users’ health.
The fear is that fake handsets, which are not subjected to safety tests, emit more radiation and contain harmful elements, such as lead.
How to spot a fake phone: Sammy Awami, BBC Africa, Dar es Salaam
The mobile phones have been switched off using a number called International Mobile Station Equipment Identity (IMEI). All mobile phones are assigned one.
Tanzania’s communication agency launched a new system in December called the Central Equipment Identification Register, which is a database of all IMEI numbers.
When paired with systems at the network providers, it is able to block all counterfeit phones.
Mobile phone users have since been urged by the government to check whether their phones were genuine or fake by:
- Dialling *#06# to get the handset’s IMEI
- Sending a text with the IMEI number to 15090
- The text reply lists phone’s model name – if the correct name is not given, the phone is a fake.
There is no doubt many counterfeit phone businesses will be affected by the switch off, but those who said they sell original phones welcomed the move.
“We will be very much benefit because… Everybody now will come and buy original phones,” said Zahoro Matelephone at Dar es Salaam’s biggest market Kariakoo.