Security personnel believed to be from the State Security Service have stormed the offices of the BBC and CNN in Lagos.
Both foreign media organizations have their offices located on the same building.
"The security operatives went to the CNN office before coming to our office," a BBC correspondent in Lagos said.
"They asked for the whereabouts of one of our personnel and later requested his telephone number, saying they wanted to speak to him," he said.
The BBC Newshour later said on its Twitter handle that "Security services leave BBC, CNN building in Lagos Correspondent tells us Nigeria wants to keep media on a short finger."
The Deputy Director Public Relations at the SSS headquarters in Abuja Marilyn Ogar denied the visit saying the media outfits had not committed any crime for the Service to investigate.
"What have they done? ... I am asking what the reason is." She said the report being circulated was unfair to the Service.
Another staffer of the BBC said Ogar has called their Abuja office denying the said unscheduled visit at their Lagos office.