Nigeria has delayed the start of the country’s school year by one month over concerns on the spread of the deadly Ebola virus.

The announcement by Nigerian Education Minister Ibrahim Shekarau on Tuesday came after reports indicated that five people died of the virus in the economic capital of the country, Lagos.

“All primary and secondary schools in private and public sectors are to remain closed until Monday, October 13,” Shekarau said. “This is to ensure that adequate preventive measures are put in place before students resume.”

According to the health ministry, Nigeria has recorded a total of 13 confirmed cases of Ebola.

Meanwhile, the United Nations criticized flight restrictions into and out of Ebola-stricken West African nations, saying the measures are preventing the delivery of critically needed medical staff and supplies.

On August 26, the World Health Organization (WHO) said more than 120 health workers had lost their lives after contracting Ebola across West Africa.

Ebola, a form of hemorrhagic fever, spreads through contact with bodily fluids such as blood, saliva, and sweat. It has killed around two-thirds of those it has infected over the last four decades, with two outbreaks registering fatality rates approaching 90 percent.

Its symptoms are diarrhea, vomiting and bleeding. There is currently no known cure for Ebola.

According to the latest official figures by WHO, a total of 2,615 infections and 1,427 deaths of the disease have been reported in Guinea, Liberia, Sierra Leone and Nigeria.