The three – one South African and two Nigerians – were reportedly attacked near the airport in Owerri, after covering a football match in Enugu.
South Africa’s foreign ministry said it was in contact with Nigerian officials but gave no further details.
It is not clear who is responsible but foreigners are often kidnapped for ransom in the nearby Niger Delta.
"The attackers ordered out more than 20 people inside the bus and took away the three and the bus," SuperSport’s general manager in Nigeria Felix Awogu told the AFP news agency.
Militants in the Niger Delta have cost Nigeria’s oil industry millions of dollars over the years.
A variety of groups have claimed to be fighting for the rights of local people to gain a greater share of the region’s wealth.
But in reality, many of the groups have stolen oil from pipelines and extracted ransoms from kidnaps, using the money to arm themselves and finance more attacks.
Source: BBC