ATHENS – Greek police arrested three Palestinians and charged them with setting a fire that destroyed a primary school in a refugee and detention camp on the island of Lesbos, one of the suspects a naturalized Greek citizen.

Authorities said CCTV footage and other information led to the alleged perpetrators, who were charged with felony arson after it was said the three took a ferry to the island that is holding some 20,000 refugees and migrants.

The fire within the Kara Tepe-area camp completely destroyed a school operated by the One happy family non-governmental organization (NGO) that is one of a number of human rights groups, activists and volunteers at the notorious Moria camp that’s been criticized for inhumane conditions.

The incident happened as thousands of migrants were released by Turkey and urged to breach the northern land border with Greece before being repelled by riot police and army units, leading Turkey to again close its border at the only spot not separated by the treacherous Evros River where many have drowned trying to cross.

Turkey is holding some 5.5 million refugees and migrants, including 3.3 million Syrians who fled that country’s civil war, with President Recep Tayyip Erdogan opening his border after the deaths of 33 Turkish soldiers in an area of Syria they had invaded led him to fear another surge.

Opening his border violated terms of a 2016 swap deal with the European Union, leading him to go to Brussels to meet bloc leaders in a failed attempt to revise the terms after he said 3 billion euros ($3.23 billion) of 6 billion euros ($6.46 billion) was being withheld.

The fire led to speculation that island residents who wanted the New Democracy government to transfer the refugees and migrants to the mainland and wanted to stop new centers aimed at vetting those ineligible for asylum were responsible for the fire.

No motive was given as yet by police as to why the school was torched on March 7 as reports said one of the suspects, 59, had a Greek passport and drove his car to take the others to the facility and had allegedly confessed.

Nine days later, a 6-year-old child died in a fire that broke out at the Moria camp’s identification center that burned shelters and tents at the facility holding about 18,000 people, six times over capacity.