Libyan authorities have arrested four Christians - a Swedish-American, an Egyptian, a South African and a South Korean – in the eastern city of Benghazi on suspicion of proselytizing and distributing religious literature.
The arrests came around the time Roman Catholic Church said nuns and priests had faced pressure to leave some areas.
News agencies reported the four foreign missionaries were arrested in Benghazi at the weekend for charges that include printing and giving out books and material that promote Christianity two years since the rebellion against Libyan dictator Muammar Gaddafi began..
South Africa's ambassador to Libya Mohammed Dangor confirmed to Independent Newspapers that a South African woman has been arrested in Benghazi.
About 97 percent of Libya's 5.6 million people are Sunni Muslims. Encouraging people to convert to another religion apart from Islam is a crime in the country.
"On the anniversary of the revolution anything could happen," Monsignor Giovanni Innocenzo Martinelli, Apostolic Vicar of Tripoli, told the Roman Catholic Fides Agency days before the second anniversary of the uprising which broke out on Feb. 17, 2011 in Benghazi.
The uprising eventually led to the collapse of Gaddafi's regime.
Before Gadhafi's fall, some groups estimated there were around 100,000 Christians in Libya, most of them foreign workers mainly from Africa, mainly from Egypt, and the Philippines as well as from India, but that number had dwindled dramatically.
Martinelli said the situation is most critical is precisely in the Cyrenaica region, of which Benghazi is the capital, where several religious congregations have decided to leave after pressure on them.
"All the nuns of various religious orders left Cyrenaica (from Tobruk, Beida, el Merj, Derna)," Martinelli told Fides. "Just the Sisters of the Immaculate Conception of Ivrea have remained who have been in Benghazi for some time."
He said the Apostolic Vicar of Benghazi, Monsignor Sylvester Carmel Magro, was advised to leave the church and find other accommodation.
"Even in Tripoli, where the situation is calm, we have been advised to be careful and not to move," said the Catholic leader noting that such a warning had been given to all Europeans in the Libyan capital.
"The city is preparing for the celebrations with joy but security measures have increased in fear of attacks," said Martinelli.
On Dec. 30 two Egyptian men were killed after assailants hurled a bomb at a building that was part of a Coptic church complex in Dafniya, near the western city of Misrata, said a military spokesman.