Supporters poured into Paris's freezing Champs-Elysees boulevard on Wednesday after a World Cup semi-final between France and Morocco which for millions tugged at the heartstrings, as "Les Bleus" won 2-0 to reach the final for a second time in a row.

Deeply enmeshed by their colonial bonds and post-war flows of migrant labor from North Africa to France, the two nations share a history that has shaped their identities and their politics, and made for a sometimes edgy relationship.

France is home to a large Moroccan community, many of whom have dual citizenship.

"We preferred to come early because it will be chaos later on. We just want to celebrate our win and we can really feel it will get crazy," said student Kerene Massuka who came with a friend carrying a French flag.

They were flanked by hundreds of police trucks securing the area as fans let off fireworks.

Crowds of supporters from both countries were seen entering the Christmas-decorated boulevard after the final whistle, where authorities were bracing for tens of thousands despite temperatures around 0 Celsius.

The stakes were high on both sides.

Morocco had a shot at becoming the first African nation to reach a World Cup final, but France are now poised to become the first team to retain their World Cup title in 60 years on Sunday.

In the French capital, Police were gearing up for possible skirmishes, after scuffles followed last week's Moroccan quarter-final win over Portugal.

Some 10,000 police officers will be mobilized nationwide, of which 5,000 personnel will be posted in the Ile-de-France region around Paris and some 2,200 in the capital, double the security staff than for earlier key World Cup matches, Interior Minister Gerald Darmanin said on France 2 television.

Morocco fans in France had been in a celebratory frenzy ever since their team went on its historic World Cup journey, becoming the first African and Arab team to reach the last four in the global showpiece event.

Celebrations have been overwhelmingly peaceful, but in some places including the Champs-Elysees, Morocco fans clashed with police.