The West African country does not share a common border with Uganda.

However, the Nigerian Centre for Disease Control (NCDC) says the high level of risk to the country is due to the "large volume of air travel between Nigeria and Uganda and the mixing of passengers, especially at the regional travel hubs of Nairobi, Addis Ababa and Kigali airports".

The health authorities say they are on alert, with a number of measures put in place to "prevent and mitigate the impact of a potential Ebola outbreak in Nigeria".

These measures include increased surveillance and screening of passengers at airports.

Nigeria has also issued a travel advisory telling its citizens and residents that they should "avoid all but essential travel to Uganda for now until public health authorities have determined the outbreak to be contained’’ in the East African country.

But when travel to Uganda is "unavoidable", travellers should avoid contact with "obviously sick persons or suspected cases of Ebola", it advises.

The NCDC says passengers coming from or passing through Uganda are being followed up for 21 days from the day they arrive in Nigeria. Response teams are also on standby for deployment in case of an outbreak, it says.

Uganda has recorded more than 100 cases and 30 deaths since the outbreak began in September, and there have been fears the virus might spread to other countries.