United Nations security staff released in Yemen after more than a year in prison

Five United Nations security staff who were kidnapped in Yemen 18 months ago and imprisoned have been released, the UN announced Friday. 

According to U.N. Secretary-General Antonio Guterres, the release is welcomed and "reiterates that kidnapping is an inhumane and unjustifiable crime, and calls for the perpetrators to be held accountable."

As of now, it is not known who kidnapped the security staff.  It comes as Iran and the United States are working on a reported agreement to free five prisoners in a swap in which Tehran will also get $6 billion released in frozen funds.