Bulgaria is working to change the regulations at some of the migrant accommodation centers across the country to boost "discipline and security", Interior Minister Rumyana Bachvarova has said.

The step could restrict movement out of or into the camp for its inhabitants, she has made clear.

Her comments follow an incident at the facility in Harmanli, southeastern Bulgaria, and an announcement that the "structure" of the inflow of irregular migrants into Bulgaria has been shifting, with numbers of Iraqi and Afghan nationals rising.

It will be precisely Harmanli that reorganization will begin with, daily 24 Chasa quotes Bachvarova as saying.

Accommodation centers in Bulgaria allow residents to leave freely and come back.

In Harmanli, however, a "curfew" has already been announced following a mass brawl that left three injured.

Many incidents in the camp are caused by residents who are under he influence of alcohol, the police chief in Harmanli has told NOVA TV in the aftermath of the scuffle.  

Nationalist VMRO party has already insisted rules should be tightened at all facilities and particularly in Harmanli, where they have been organizing a forthcoming protest of locals calling on camp authorities to enforce "discipline" on the migrants.

Separately, the center in Harmanli is to be expanded to make room for 300 more people.