Libyan security forces said Thursday they had arrested a second US citizen for alleged Christian proselytising in the North African Muslim nation.
The arrest came a day after another US citizen, who was also teaching at the same private language school in the capital Tripoli, was detained for "inciting our children to renounce Islam and convert to Christianity".
On Thursday, the Internal Security Agency said it had arrested the centre's assistant director in Tripoli, identifying him by the initials "SBO".
It accused him of operating "in the company of his wife as a missionary on behalf of the organisation 'Assemblies of God' in order to seduce the sons of our Muslim people".
Assemblies of God is a missionary organisation based in southern US state of Arkansas.
While the security forces have not named the man arrested on Wednesday, Libyan media identified him as Jeff Wilson, the founder of the consulting firm Libya Business.
Libyan security forces said Thursday it had also arrested two Libyans, including a 22-year-old woman who had allegedly converted to Christianity when she was 15.
In a video, she describes how she in turn became a "missionary" and tried to persuade other Libyans to switch faiths.
It is the latest of a handful of video "confessions" of "apostasy" in Libya.
Islam is considered the state religion in Libya, and while Christians have the freedom to worship there, the majority are foreigners living in the country.
Control of Libya is divided between two rival governments, the latest configuration in years of turmoil since the 2011 NATO-backed uprising that toppled former dictator Muammar Gaddafi.