SOFIA (AFP) - Bulgaria's interior minister announced on Monday an action plan aimed at speeding up expulsions of economic migrants, as the EU's poorest country grapples with a sharp rise in refugees.

Mr Tsvetlin Yovchev said that migrants "who have no grounds to request humanitarian or refugee status" would be expelled from Bulgaria within three days.

"Those whose case requires a deeper investigation will be housed in centres that they will not be allowed to leave of their own free will," he told a news conference.

"People who visibly have a humanitarian problem, in particular mothers with children, will be housed in shelters" and their requests examined in a fast-track procedure, he said.

Bulgaria has had to cope with a steep increase in refugees, 60 per cent of them Syrians, with some 8,800 arriving so far this year, well above the country's 5,000 annual capacity, Mr Yovchev said.

Those who brave it over the border from Turkey are housed in overcrowded detention centres in a country already struggling to tackle dire poverty among its own citizens.

With press coverage becoming increasingly anti-immigration, tensions were stoked on Saturday by the alleged stabbing in Sofia of a woman by an Algerian who had applied for asylum.

This led to nationalist demonstrations by several hundred people on Sunday and on Monday.

Mr Yovchev also said he expected the number of refugees to fall sharply from next year due to increased security measures along the country's mountainous border with non-EU Turkey, the main crossing point.