Greek police officials say Macedonian authorities have imposed further restrictions on refugees trying to cross the border, saying only those from cities they consider to be at war can enter.

The officials said the restrictions imposed Sunday means that people from Aleppo in Syria, for example, can enter Macedonia from Greece, but those from the Syrian capital of Damascus or the Iraqi capital of Baghdad cannot.

The officials spoke on condition of anonymity because they weren't authorized to speak on the record.

The restrictions were the latest move by Macedonia to slow the flow of refugees into the country. The rate at which refugees are being allowed to cross had already been reduced to a trickle and about 13,000-14,000 people are stranded in an overflowing camp on the Greek side.