Tensions between Serbia and Croatia have escalated as the Balkan states struggle to come up with a way to deal with tens of thousands of refugees streaming through the two countries to seek sanctuary in other parts of Europe.
Serbia banned imports from Croatia on Thursday to protest against Zagreb's decision to close the border to cargo as the countries criticised each other for their handling of refugees who are travelling through Serbia, then onto Croatia, on their way to Western Europe.
Croatia responded by banning all Serbian-registered vehicles from entering the country.
The increasingly acidic tone of exchanges is reminiscent of that used during the wars that accompanied the disintegration of Yugoslavia in the 1990s, when nationalists on both sides capitalised on the country's economic collapse and fanned ethnic tensions.
"We responded with economic measures without disrespect for Croatian citizens," Serbian Prime Minister Aleksandar Vucic said.
"Within 15 minutes, they responded in a way that reminds us of the events from the 1990s, and we wish to forget that.
"We will not respond to this, because I simply do not know how to respond to that and stay an honest and normal person."
Croatia's move cut Serbia off from many of its main trading partners in Europe, with the decision costing each nation as much as $1m a day.
The tit-for-tat actions underscore the pressure exerted by thousands of people from the Middle East, Africa and Asia who are transiting the Balkans in hopes of making their way to countries such as Germany and Austria.
Relations began unraveling after Hungary closed its border to the refugees earlier in September, redirecting tens of thousands through Croatia .
Croatia has opened a transit camp in hopes of inserting order into the chaos and to provide the thousands with food, water and medical attention, but people keep coming, and nerves are frayed.
"No one is moving. No one," said truck driver Dusko Strelja at the border in Bajakovo, Croatia.
"The Red Cross is bringing us food here."
Croatia has shut all but one of its crossings with Serbia to block the movement of refugees, which continues unabated after 51,000 people entered the country in little more than a week.
Croatia is angry that Serbia is busing refugees to its border, rather than sending them north to Hungary.
Croatian Prime Minister Zoran Milanovic on Thursday accused Serbia and Hungary of colluding.
IN PICTURES: Refugees at Croatia - Serbia border
"I won't allow that they make fools out of us and that they are sending all [refugees] to Croatia," Milanovic told reporters.
Serbia's foreign ministry, in a strongly worded protest note to Croatia, said the latest measures were "discriminatory" against Serbs and compared them to the actions of the Nazi puppet regime in Croatia during World War II.
Even before the present chaos, progress in relations between Croatia and Serbia had been hard-won. A prolonged crisis is certain to add more pressure to such ties.
"From Serbia, we are demanding little: don't send people in such numbers into Croatia," Milanovic said. "We don't want 50 camps on our borders."
The vast majority of refugees do not wish to remain in either country.
"They are waiting for buses, they are in hurry, they get nervous, anxious," said Idriz Besic, an imam from Gunja, Croatia, who was visiting the refugees at the transit camp of Opatovac.
"The worst thing is that a lot of families are missing members. They are missing children, wives, brothers. The situation is terrible."
|A girl makes her way towards the Croatian border with Hungary [Reuters]