Macedonian police have fired tear gas and stun grenades to drive back refugees trying to cross the border from Greece after they spent a night stranded by an emergency decree that has effectively sealed the Macedonian frontier.

At least four refugees were taken for treatment on the Greek side of the border, Al Jazeera’s Ivan Corkalo reported on Friday. Officials said 10 people in total were injured.

Witnesses said the border reopened around 4pm local time (1400 GMT) after being closed overnight.

More than 3,000 people had been waiting on the Greek side for the border to open, our correspondent said.

Macedonia deployed several hundred policemen and soldiers to secure the frontier.

“They shoot us today, they shoot us today, I can tell you, I see it. We was in front of the place. Officer people, they… Officer people in Macedonia, they shoot the people,” a refugee, who did not want to be identified, told Reuters.

Refugees from the Middle East, Africa and Asia, many of them Syrians, spent a cold night on the border on Thursday as Macedonia declared a state of emergency and effectively blocked its southern frontier to refugees fleeing war.

The flow into Macedonia had reached 1,500-2,000 per day in recent weeks, up from some 200 daily in May, leading to desperate scenes of crowds wrestling to board packed trains at a nearby railway station, children squeezed through open carriage windows.

An AFP photographer said police in riot gear fired tear gas grenades sending up clouds of smoke as hundreds of migrants, including women and children, gathered at the border fence.

Macedonian justified its moves on Friday, saying it wanted to boost the security of settlements in the area and to deal more efficiently with the rising number of refugees.

The Interior Ministry, in a statement, said its measures were working and that it had admitted 181 foreign nationals overnight – “a limited number of migrants of vulnerable categories who could be adequately treated in line with the country’s capacities”.

The measure could create a huge backlog of refugees on the Greek side of the border.

“We can’t believe that we are here from this morning,” Ahmet Husa of Syria told Reuters. “People from Syria escaped from war, escaped death and we want to see our future in Europe. We need this road to see our future.”

Thousands of refugees are holed up in Macedonian town of Gevgelija, from where they planned to catch trains that would take them to the Serbian border on their way to Hungary.

Hungary has begun erecting a fence to try to keep the distraught refugees out.

Macedonia appealed on Wednesday for neighbouring countries to send train carriages to address the demand. Al Jazeera