The BBC reports that 13 kidnapped Egyptian Coptic Christian workers have been freed Jan. 5; they were suspected to be abducted by Islamist militants  in northern Libya around 2:30am on Jan. 3.

This is the latest in a series of attacks on Egyptian Christians in Libya and occurred only a week after seven others were abducted in a separate incident.

On Saturday, Christians and Muslims were reportedly separated before being handcuffed and kidnapped. “They had a list of full names of Christians in the building. While checking IDs, Muslims were left aside while Christians were grabbed,” Hanna Aziz told the AP news agency.

According to the pan-Arab newspaper Alshareq Alawsat, Egyptian intelligence sources have said that “despite current information stating  the organisation ‘Fajer Libya’ is behind the attacks, initial reports confirm the responsibility of Islamic State’s Libyan branch”.

Ahram Online, an Egyptian news agency, said Egypt’s foreign affairs ministry is calling “Egyptians not to travel to Libya”. The Ministry said that it is monitoring the situation among “very complicated circumstances and chaos, especially as there is no Egyptian [diplomatic] presence in Libya.”

Alshareq Alawsat said the number of Egyptian Christians in Libya has dramatically dropped from 100,000 due to general instability and that no more than a few hundred remain in the city of Sirte – where the Jan 3. kidnapping occurred.

The Bishop of the Coptic Orthodox Church in the UK said “In recent years Coptic Christians in Libya have endured horrific acts of brutality that include the bombing of churches, abductions, torture, and execution style murders. In recent weeks alone we have seen the murder of a Coptic Christian couple and their thirteen year old daughter in Sirte.”

In 2014 more than a dozen Christians were killed in Libya.