Five staffers for the humanitarian group Doctors Without Borders (MSF) were taken from a Syrian home on Thursday night, "apparently for questioning," according to a statement from the organization on Friday. There are no details at this time on who took the group's workers, or for what precise reason. MSF has declined to identify the names of their staff members, or the exact location from which they were taken. "MSF is in contact with all the appropriate actors as well as the families of the colleagues and is doing everything possible to reestablish contact with these colleagues," spokesperson  Samantha Maurin added. 

This isn't the first time aid workers in the country have been targeted. In October, the al-Qaeda-associated Islamic State of Iraq and the Levant (ISIL) was accused of kidnapping seven International Red Cross workers in the country. In September, an MSF doctor died while working in a northern hospital to treat victims of the years-long conflict in the country. Aid worker kidnappings have surged over the past year, Reuters argues, as the balance of power in the country becomes even more fractured. They wrote in October: 

Some aid agencies have had to adapt their work, others are scaling back. "The security situation has got much worse in recent months, especially in August, given the rise of the influence of extremist groups directly linked to al Qaeda," said Jitka Škovránková, who works for the Czech People in Need, one of the few aid groups working in Aleppo city, in north Syria.

She said fighting between al Qaeda-linked groups and other rebels as well as Kurdish groups along the Turkish border had made her organization change the way aid enters Syria.

In August of last year, Doctors Without Borders had to abandon the nation of Somalia, because it simply became too dangerous to operate in. The rise in threats in the last several years, show that some warring groups simply no longer consider humanitarian workers to be off-limits, as they have been in the past.

Journalists working in Syria are also vulnerable to kidnappings: at least 30 reporters have gone missing in the country while covering the war, often taken by jihadist groups angry about negative coverage or for bargaining leverage for future use, according to an AP report from late last year. Those still missing include four American journalists: Washington Post freelancer Austin Tice, GlobalPost freelancer James Foley, and two other journalists whose families would prefer not to release their names, fearing that too much publicity will only make their situations worse. 

MSF did not release the nationalities of the five workers taken this week.