At least five people have been hurt when Macedonian police threw noise grenades to drive back migrants from the country's border with Greece, the latest flashpoint in Europe's growing refugee crisis.
More than 3000 mostly Syrian refugees are stuck in no man's land near the Greek village of Idomeni after Macedonia declared a state of emergency on Thursday (local time) and sent troops to help stem the flow of migrants attempting to cross the small Balkan country to reach northern Europe.
Police in riot gear fired the grenades on Friday after hundreds of migrants, including women and children, tried to cross newly laid rolls of barbed wire along the frontier.
The grenades sent up clouds of smoke and sent the refugees running for cover, an AFP photographer reported, with those hurt were only slightly injured with cuts to their legs from fragments of the grenades as they exploded.
The confrontation lasted only a few minutes with the migrants trying to calm the situation by putting women and children between them and the police.
The Macedonian authorities, however, denied any clashes had taken place. Interior Ministry spokesman Ivo Kotevski said there was "no incident, no tear bombs ... nothing like that on Macedonian side".
Police had earlier prevented reporters from accessing the no man's land where on Thursday officers had been in a stand-off with about 1500 migrants and refugees who wanted to cross into Macedonia.
But with the numbers of refugees blocked on the Greek side building up during the night, tensions rose.
"The Macedonian police told us last night that they would allow us to cross at 10am but they didn't," a 27-year-old Syrian said.
Macedonian police also stepped up their presence at the train station in the border town of Gevgelija, where thousands of migrants who had been arriving daily previously were given temporary documents, allowing them to cross Macedonia so they could travel on to Serbia and the main European Union frontier.
But on Friday, police were not issuing the documents to newly arrived groups, prompting exhausted refugees to fear that they would be sent back to Greece.
"They don't give us papers, so maybe they want to bring us back to Greece," a 24-year-old man from Damascus said.
"We don't want to go back, we are very exhausted from walking," said the biology student, who asked not to be named.
"We are exhausted from the situation in Syria. My father died from a shell. I had to leave, I have no one there anymore. I want to continue my education in some other country, I don't want to go back to Syria," he said.
But a few hundred Syrians did manage to slip across the border during the night, witnesses said, taking to the forested hills with the help of the GPS on their mobile phones to walk around police and army lines concentrated on the plain below.