(File photo: AFP)

VALLETTA, Sep. 25 (Xinhua) -- Migrants currently being held at a detention center in Malta staged a protest demanding freedom on Wednesday.

The protest began around 12:00 noon local time. Police units were dispatched to the site.

This is not the first time migrants have held a protest against their detention. Earlier this month, migrants scaled wire walls and unfurled banners demanding "freedom." A fire was also lit during that protest.

The migrants are being held at the Hal Safi detention center on medical grounds after being disembarked in Malta. Earlier this month, local non-governmental organizations called for their immediate release.

The NGOs said that migrants can only be detained if their detention is clearly and objectively justified on medical grounds. They also recalled that arbitrary detention is unlawful.

Currently there are more than 800 people detained at Hal Safi.

During Wednesday's protest, the migrants held up banners, clapped and chanted "freedom."

On Monday, a mini-summit was held in Malta, during which five European Union home affairs ministers agreed on a position paper on the disembarkation and relocation of migrants.