Nigeria's government has denied the assertion by cyber security firm Fortinet that the country was the third most affected by the WannaCry ransomware attacks, after South Africa and Ivory Coast.

Director-General of the National Information Technology Development Agency (NITDA), Dr Isa Ali Ibrahim Pantami said that there were no reported incidences in Nigeria.

"Traces in Nigeria appeared to be isolated cases as no major incident is reported in the country. As IT systems have now become part of our lives, the need for all to be vigilant and proactive as far as security is concerned cannot be over-emphasised," said Dr Pantami.

"Nigeria was largely spared from the attack due to the massive enlightenment campaign, awareness and proactive measures put in place to swiftly deal with any reported incident," he added.

During the outset of the cyber-attack, the NITDA and the Nigerian Communications Commission (NCC) informed citizens of what they could do to avoid falling victim to attacks.

Local IT experts have suggested the development could be as a result of the country's poor tech reporting system since many affected individuals are not aware of the existence of any cybersecurity reporting system.

"The government should know that because no one reported to its agencies does not mean no one was attacked. People have been dealing with ransomware in Nigeria long before WannaCry," said local tech expert Seyi Olusanya.

According to a breakdown of global attacks by Fortinet, healthcare was the most targeted sector, followed by transport and logistics, food & beverage, and media. And against the Nigerian government's claim that the attack has been contained, Fortinet warned that it continues to spread quickly.

Dr Pantami encouraged citizens using old operating systems to upgrade them to the latest version in order to get the latest protection from Microsoft;

"The recent security update released by Microsoft, MS17-010, should be installed as soon as possible; and Where necessary, Windows Defender Antivirus should be enabled as it helps in detecting this ransomware and similar attacks," he added.