This article is more than 4 years old

This article is more than 4 years old

France will reinstate controls on its borders – normally open to countries in Europe’s free-travel zone – for the period around a UN climate conference in Paris, the interior minister has said.

Authorities are on alert for violent protesters as well as potential terrorist attacks around the conference, which takes place from 30 November to 11 December. Eighty heads of state, including President Barack Obama, and tens of thousands of other people are expected in Paris for the opening.

Bernard Cazeneuve said on BFM TV on Friday the controls would be in place for a month “in the context of terrorist threats that could come and stain this large international gathering that is carrying a grand message for humanity”.

Europe’s so-called Schengen zone of countries with open borders allows for occasional reintroduction of internal border checks, which some countries have done during this year’s migrant crisis.

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France submitted a note to EU authorities last month announcing border checks at all airports with international flights and at 131 land crossings with Belgium, Germany, Spain, Italy, Switzerland and Luxembourg. It cites Schengen rules allowing controls “when there is a serious threat to public policy”.

France is still reeling from deadly attacks by Islamic extremists in January on the satirical newspaper Charlie Hebdo and a kosher grocery store. Since then, several smaller attacks or attempts have occurred in the country: in August, a heavily armed Islamic radical was prevented by American passengers from attacking a high-speed train. France is also bombing Islamic State targets in Syria and Iraq as part of a US-led coalition, and has troops fighting extremists in Africa.

The climate conference aims to reach the most ambitious accord to date for world governments – to reduce emissions that cause global warming.

Organisers expect at least 40,000 people in addition to tens of thousands of activists from environmental, human rights and other groups from around the world. A big march is planned through Paris on 29 November, and protest groups plan to try to blockade the conference site 11 and 12 December.

France faces routine protests that are largely peaceful but sometimes degenerate into violence by an extremist fringe. There were particularly violent protests during a Nato summit in Strasbourg in 2009, when members of the violence-prone “black bloc” attacked police and set a hotel and customs station ablaze, leaving many injured and disrupting official meetings.

The US embassy in Paris has warned American citizens to be particularly vigilant around the climate conference.

The last time France reinstated national border controls was for a G20 summit in Cannes in 2011.