The official noted that the reopening of airports and increased local and international travels also fuelled the rise in coronavirus cases.
The reopening of schools and religious centres without adherence to safety protocols contributed to the rise in COVID-19 cases across Nigeria, an official has said.
The Chairman of the Presidential Task Force (PTF) on COVID-19, Boss Mustapha, made this known at its briefing on Monday.
He noted that reopening of airports and increased local and international travels also fuel the rise in coronavirus cases from late November 2020.
"It is however very instructive to stress that factors that have contributed to rise in numbers from late November 2020 included increased local and international travels, business and religious activities, reopening of schools without strict compliance with COVID-19 safety measures," Mr Mustapha said.
Since early December, there has been a spike in coronavirus cases across Africa's most populous country, an indication that the country had entered the second wave of the pandemic.
A recent review by PREMIUM TIMES shows that one in every six persons (16 per cent) tested for COVID-19 in Nigeria in the past two weeks tested positive, indicating how fast the virus is spreading.
Health experts believe the lowering of guard on safety and the weak enforcement of protocols especially in the country's major airports in Abuja and Lagos could be responsible for the development.
They warn that the situation could get worse if citizens keep violating safety protocols.
The federal government recently warned that a significant increase in COVID-19 infections in Nigeria appears imminent this January due to the violation of safety protocols during the Christmas period.
To tackle this, federal authorities have ordered the reopening of all isolation and treatment centres.
The Nigerian government also reintroduced new restrictions to check the spread of the virus, including the closure of bars and nightclubs and limiting the number of people allowed in a public gathering.
Nigeria, on Monday, crossed the 100,000 milestone in infections. The country, as of the time of this report, had recorded 100,087 cases of the virus and 1,358 deaths.
The number of coronavirus infections worldwide also surpassed 90 million on Sunday morning, about a year since the highly infectious disease began spreading around the globe.
Africa accounts for over 3 million of the confirmed cases, according to the Africa Centers for Disease Control and Prevention.
At the briefing in Abuja on Monday, Minister of State for Health, Olorunnimbe Mamora, said the rising cases of infections impose an enormous burden on Nigeria's health facilities.
"With the increased number of confirmed cases, the number of active cases has increased. As of today, we have 18,699 active cases on treatment both in facility and in the community using the treatment protocols.
"Many of the active cases may require care in one of the treatment or isolation centres thus imposing enormous burden on our facilities," he said.
Mr Mamora also said results from the tests conducted on prospective NYSC members have confirmed that no part of the country is free of COVID-19 disease.
"We safely and comfortably draw this conclusion because corps members are mobilised from all the states of the country for each of the orientation camps," he said.
The minister noted that plans regarding activation of oxygen availability in various states is on course with a view to effecting immediate repairs of non-functional oxygen plants.