Four employees of a French Christian NGO, three French nationals and one Iraqi, have been missing in Baghdad since Monday, the charity announced Friday.

The four members of the influential SOS Chretiens d’Orient (Christians of the Middle East) charity went missing near the French embassy in the Iraqi capital, the organization’s director Benjamin Blanchard told a press conference in Paris.

No ransom demand has been received as yet and no group has claimed responsibility for their disappearance, he added.

SOS Chretiens d’Orient has been working with Christians in Iraq since 2014 when ISIS overran the province of Mosul, displacing tens of thousands of minority Christians and Yazidis.

It is principally active in the Iraqi Kurdish capital Arbil, where many Christians sought refuge.

The missing team was in Baghdad “to renew their visas and register the association with Iraqi authorities,” Blanchard said, adding that they were “experienced staff members who have been working with us for years.”