Lagos, Nigeria -- Nigeria's president ordered security forces Tuesday to step up their search for 15 children kidnapped in the country's southeastern region when gunmen hijacked a school bus.
President Goodluck Jonathan condemned the "utterly callous and cruel kidnapping" of 15 nursery and primary school pupils on Monday.
A statement from the president's office said the Nigerian leader order the Inspector-General of Police and heads of other security agencies "to take all necessary steps to rescue the abducted children and return them safely to their parents."
The incident occurred near Aba, the capital of Abia state.
Kidnapping has been rampant in the region for years. In this case, the abductors are asking for a ransom of 20 million naira, or nearly $130,000
Police don't know the whereabouts of the children, and they won't confirm their nationalities and identities.
Geofrey Ogbonna, the state's police spokesman, said four gunmen boarded a bus headed to Apayi International School in Aba and took the children away.
The bus driver and the school teacher who were on board are in police custody and helping law enforcement efforts.
Jonathan urged the children's parents and relatives "to remain calm" and assured them that the government "will do everything possible to apprehend the kidnappers and bring closure to these ugly incidents as soon as possible."
Militants in the southern oil-producing region, who have been fighting for years over fairer distribution of the country's oil wealth, have abducted oil workers, and people engaged in criminal activity have snatched up citizens to get ransom money.
Kidnappings and rape in Abia state are common and have become more frequent in recent years. They include vehicle hijackings and even people being snatched off the street. The motive is usually money.
Some people travel with security -- if they can afford it. As foreign oil workers improved their personal security, the kidnappers have increasingly targeted Nigerians.