Ventimiglia, an Italian town of 25,000 inhabitants just six kilometers away from the French border - up until now marked only by a sign - has become a symbol of resurrecting frontiers amid a growing spat between the two countries, in spite of a free-travel policy signed in 1985 some 900 km to the north, in the Luxembourgish village of Schengen.

Trains coming from Ventimiglia on Sunday and carrying some 300 Tunisian migrants and political activists wanting to make a point about the French opposing freedom of movement were stopped at the border for hours, prompting Italy to lodge an official complaint via its ambassador in Paris. The Italian foreign ministry called the move "illegitimate and in clear violation of general European principles".

This comes after weeks of enhanced border checks and reported push backs to Ventimiglina of Tunisian economic migrants who were trying to come to France. Some 26,000 migrants have arrived to Italy since the ousting of dictator Ben Ali in January, but most of them did not apply for refugee status and were free to leave the reception centres on the Italian mainland, which are designed for asylum seekers.

The Italian government on 5 April signed a deal with the Tunisian authorities to return any new migrants arriving on the shores of Lampedusa, the most southern Italian island which is closer to the Tunisian coast than Sicily.

But the deal does not cover the return of those migrants who arrived prior to 5 April. Rome has therefore issued temporary "humanitarian" residence permits, allowing the migrants to stay up to six months in Italy and travel to other Schengen countries.

France, however, is contesting the legality of the permits and says the migrants still have to make proof of having enough financial means in order to cross the border, which is now de facto re-instated.

"We have given the migrants travel documents, and we gave everything (else) that is needed, and the European Commission recognised that, it has said that Italy is following the Schengen rules," Italian Interior Minister Roberto Maroni said in an interview on Italy's Sky TG24 TV.

He added that some 330 Tunisians have already been repatriated since the signing of the bilateral accord.

Meanwhile, in an interview to several French media outlets, EU council President Herman Van Rompuy on Sunday urged the immigration issue not to be blown out of proportion.

"Of course there's a risk of migration, but we must not exaggerate it," the former Belgian Prime Minister said.

"Neither Italy, nor France has yet done anything illegal. That said, there is a danger of their not respecting the spirit of the Schengen treaty on free movement," he added.

EU leaders will discuss the issue at a summit in Brussels, on 24 June.

On the eastern flank, new member state Romania, who last year had its own migration issue with France, over the 'voluntary' repatriation of hundreds of Roma carried out by the French government, offered to take up to 200 Tunisians in a sign of "solidarity" with Italy.

"After talks with the government and the relevant institutions, we have decided to inform (Italian) Prime Minister Silvio Berlusconi that Romania can host 200 migrants," Romanian President Traian Basescu said during a press conference.

France has also opposed Romania's bid to join Schengen in March, initially citing the Roma issue and later teaming up with Germany in invoking corruption and judiciary problems.

Link to the newssite of EUobserver: EUobserver.com.