Masked gunmen in central Libya kidnapped 13 Coptic Christians on Saturday, and seven others were abducted days earlier, a witness and a priest from the community said. The incidents highlight a new wave of assaults against Christians from Egypt working in Libya, a country that has been plagued by worsening instability since the fall of dictator Moammar Gaddafi in 2011.

Gunmen went room to room in a residence for Egyptian Christian workers in the Libyan city of Sirte at 2:30 a.m. Saturday and asked for identification papers to separate Muslim workers from Christians, witness Hanna Aziz told The Associated Press. The gunmen handcuffed the Christians and drove away with them, Aziz said.

"They were 15 armed and masked men who came in four vehicles,” he said. “They had a list of full names of Christians in the building. While checking IDs, Muslims were left aside while Christians were grabbed. I heard my friends screaming, but they were quickly shushed at gunpoint. After that, we heard nothing. I am still in my room waiting for them to take me. I want to die with them." Aziz, who said he has three relatives among the hostages, added that he survived simply because he didn't open his door.

Abu Makar, a Coptic priest in the workers' hometown of Samalout in southern Egypt, said that seven other Coptic Christians from Samalout were abducted while trying to escape Sirte a few days earlier. The city, located in northern Libya between Tripoli and Benghazi, has become a safe haven for extremist groups like Ansar al-Shariah, which the United States blamed for the September 2013 attack on the its consulate in Benghazi that killed U.S. Ambassador Chris Stevens.

There was no immediate comment on the reported abductions from the Egyptian government. On Wednesday, Egypt’s Foreign Ministry said that it is following up on the case of the first group of seven abducted Christians.

Since fall of Gadhafi in 2011, Libya has struggled to overcome instability with heavily armed rival factions who once fought side by side to oust Gadhafi now competing for power.

Libya has had two governments and parliaments since a group called Libya Dawn seized control of the capital Tripoli in August. The internationally recognized prime minister, Abdullah al-Thinni, was forced take refuge in the country's east as a result. Libya Dawn set up its own government, taking over ministries, and forcing Thinni and the elected parliament to move to the eastern city of Tobruk.

Extremist militias have been targeting Christians, women, journalists, refugees and those considered former loyalists of Gaddafi, who was toppled and killed in Libya's 2011 civil war.

Egyptians have become a top target for the militias since the Egyptian government began supporting the Libyan army in October in its fight against militants. "We are witnessing a pattern of persecution against Christians in Egypt," said Magdi Malak, a Cairo-based activist involved in the Sirte abduction case. “I fear for the lives of the hostages.”

Hundreds of thousands of Egyptians, both Muslims and Coptics, work in Libya, mostly in the construction and trade sectors. They have been the targets of several recent attacks. In December, a Coptic couple who worked as doctors in Sirte and their daughter were killed by unidentified armed men. In March 2014, the bodies of seven Christian Egyptians were found in the eastern city of Benghazi, killed by gunshots to the head while handcuffed.

In March 2013, dozens of Coptic Christians were tortured inside a detention center run by a powerful militia in Benghazi, who suspected the Christians of proselytizing. They were rounded up in a market by gunmen, who checked their right wrists for tattoos of crosses, a common mark worn by many Egyptian Christians.