Belgium Asylum and Migration Minister Theo Francken attends a ministerial meeting of the Justice and Home Affairs Council at the European Council in Brussels, on December 5, 2014. Photo: Emmanuel Dunand via AFP/Getty Images. | Emmanuel Dunand/AFP via Getty Images Security concerns flare up over Greek asylum centers EU agency boosts safety measures in Lesbos after riots last week.

The EU's asylum agency is stepping up security measures at refugee facilities on the Greek islands, after recent incidents of violence have forced authorities to evacuate staff.

The European Asylum Support Office, which coordinates EU efforts to help Greece with the processing of asylum requests, said "a number of security measures have been taken while other measures are ongoing," according to a letter the agency's executive director, José Carreira, sent the Belgian government Friday, a copy of which was obtained by POLITICO.

Riots broke out at an asylum center on the Greek island of Lesbos last week in what was called the worst incident in any such facility since the start of the migration crisis. The center's international staff members, including asylum officers and interpreters from different EU countries, were evacuated from the premises after fires were started.

EASO's measures include a number of fixes to the center on Lesbos. "There is no assembly area and no easy way to exit from the area beyond the emergency exit as there is a rather deep ditch," Carreira wrote, adding that officials were working to solve these issues.

Other measures include installing better alarm systems, adding fire extinguishers and medical kits, and "[b]arbed wire around the entire interview perimeter." Greek police will be deployed to the center when asylum processing resumes Wednesday, after the Greek Easter break.

Belgian State Secretary for Asylum Theo Francken voiced his concerns late last week to EASO and the Greek government, which administers the center. "[Security] really has to improve, and has to improve quickly," Francken said Monday, adding that the Greek government has to take action "within days."

At a meeting of EU interior and justice ministers later this month, Belgium will push for an audit of the security situation in the centers, the state secretary said. "Security really is priority — if something happens, European countries won't want to dispatch people [to the centers] anymore," he said.

Greek government officials did not respond to requests for comment about the security situation.

It is not the first disagreement between Belgium and Greece over the handling of refugees. In January, after an EU ministerial meeting, Greek Migration Minister Yiannis Mouzalas claimed Francken told him to "push" migrants "back in the sea" instead of processing their asylum requests.