The aid workers – two Danes working for the NGO Team Humanity, and three Spanish citizens with the organisation PROEM-AID — were detained Thursday when coastguards patrolling off the island of Lesbos found two of them in possession of knives and an undeclared two-way radio.
The prosecutor in Lesbos' main town Mytilene on Thursday opened proceedings against the group on suspicion of “attempting to facilitate the entry of illegal migrants”, and they were questioned over the weekend.
“The five detained people have been freed,” an official with the island's port police told AFP, without saying who, if anyone, had been charged.
The three Spaniards were identified as Julio Latorre, Manuel Blanco and Enrique Rodriques, all firefighters from Seville who had volunteered with PROEM-AID.
They have spoken of their arrest and complained of the “inhumane” jail conditions where they were held for three days.
Latorre complained that they had been treated aggressively by the police. “We were thrown together in a cell 3m by 3m that was very dirty and with a toilet that was … inhuman,” he said in an interview with El Pais newspaper.
“Later we were told we would be taken before a judge accused of illegal trafficking. We were handcuffed and treated as if we were terrorists,” he said.
Greek authorities have in recent days begun a more stringent inspection of the aid groups operating on the holiday island – which saw half a million migrants pass through last year on their way elsewhere in Europe – in a bid to improve rescue coordination.
Seven volunteers – including three Britons, two Americans, a Dane and a Cypriot – had been arrested last week on suspicion of stealing lifejackets left behind by refugees.
They were later released after convincing the authorities that they intended to use the lifejackets for makeshift bedding for the migrants.
— Refugee Support (@refugee_supp) January 16, 2016
Peter Bouckaert, emergencies director at Human Rights Watch, criticised the spate of arrests, saying NGOs were filling a “crucial gap in capacity” as cash-strapped Athens struggled to cope with the flow of arrivals.
“The work of volunteers on the Greek islands is of critical importance, and saves lives,” he wrote on Facebook.
“Those crucial activities should be facilitated by the Greek authorities, and not impeded.”
PROEM-AID said on its Facebook page that the three Spaniards had not been charged, but that Greek authorities were demanding a deposit of €15,000 ($16,400) from the NGO while they continue to investigate.
“Manuel , Julio and Kike have been released without charges, interim measures are not imposed and they will return home very soon,” the NGO said.
“However, the Greek authorities continue to investigate the case and demand that PROEM -AID pay a guarantee of €15,000 euros, and they will request them to return if necessary.”
Greek islands in the Aegean Sea saw more than 800,000 migrants – many of them refugees fleeing war-torn Syria – land on their shores from Turkey in 2015, their first EU stop on a journey to new lives in Germany, Sweden and elsewhere.
More than 3,700 migrants died or were reported missing in the Mediterranean in 2015 while making the dangerous crossing, 800 of them while trying to make it to Greece and the rest heading towards Italy.