Paris - The discovery of Afghan evacuees representing potential security risks in France and Britain has put the spotlight on screening efforts during the evacuation operation with Western diplomats working under extreme pressure in Kabul.

Five Afghans who arrived in France in recent days have been placed under surveillance for possible links to the Taliban, including one who was detained after he briefly breached control orders imposed by security forces.

In Britain, Armed Forces Minister James Heappey said Monday that there were "people trying to take advantage of this process to get into the UK to cause us harm" following reports that five potentially dangerous individuals had tried to board planes.

One of them on a so-called "no-fly list" succeeded in travelling to Birmingham, central England, where he was investigated and deemed "not a person of interest to the security agencies or law enforcement", the interior ministry said.

Politicians in both countries have sought to reassure the public, underlining that the systems in place to weed out dangerous individuals from the Taliban, Al-Qaeda or Islamic State group are functioning.

During the 2015 migrant crisis in Europe, several Islamic State members who later plotted attacks in Paris are known to have concealed themselves in the mass of people who fled the Syrian civil war through Turkey, Greece and other EU countries.

"We know all of the people who have arrived on our territory, brought back by the army," Interior Minister Gerald Darmanin told Franceinfo radio on Tuesday shortly after a new flight carrying around 200 Afghans landed in Paris.

The main suspect among the five people under surveillance in France has confessed to being a member of the Taliban, but he also assisted with evacuation efforts "at an incredibly tense moment and probably saved lives," government spokesman Gabriel Attal said on Tuesday.

In Britain, Defence Secretary Ben Wallace said the country's security systems had proved their effectiveness.

"I wouldn’t be as alarmed as some of the media headlines are about this individual and I would also take some comfort from this process is working and flagging people," he told Sky News on Tuesday.

- Checks on arrival -

About 50,000 foreigners and Afghans have fled from Kabul's airport since the Taliban swept into power nine days ago, according to the US government.

Many Afghans fear a repeat of the brutal Taliban regime of 1996-2001, and retribution for working with the US-backed government over the past two decades.

Graph showing the number of people evacuated from Kabul (as of August 24)

Chaotic scenes at the airport have seen Western diplomats and soldiers besieged by desperate civilians seeking visas to travel before an August 31 deadline when US forces are meant to withdraw from Afghanistan.

The strategies for vetting refugees vary from country to country.

France is flying all evacuees to a military base in Abu Dhabi where they undergo a first round of checks, Darmanin explained, with the DGSI domestic security agency then taking over the process once the Afghans arrive on French soil.

Belgium and Germany are carrying out security checks on new arrivals once they arrive.

A spokesman for the German interior ministry said "less than 10 people" had been found to have an existing criminal record in Germany during these checks.

The online Focus media reported that three people had been identified as having been previously expelled from the country for crimes including drugs offences and rape.

- Russian worries -

The arrival of thousands of refugees is a politically sensitive issue for governments in Europe where far-right anti-immigration groups have grown in popularity in recent years, particularly after the 2015 migrant crisis.

In France, migration is due to be one of the most contentious issues in next year's presidential elections when President Emmanuel Macron could face a duel with far-right leader Marine Le Pen, while Germany will elect a new parliament next month.

Map showing countries where jihadists are operating

"The 'duty' of a welcoming France takes a back seat when the security of the French is in danger. This makes perfect sense to everyone -- except the government," Le Pen wrote on Twitter.

Russian President Vladimir Putin has also expressed concerns about the danger of extremists using refugee flows from Afghanistan as cover.

"Our Western partners are persistently raising the question of placing refugees in Central Asian countries before obtaining visas to the United States or other countries," he told a meeting of officials of the ruling United Russia party on Sunday.

"But who is among these refugees? How can we know?," adding that "militants under the guise of refugees" might try to reach Russia.

The far-right in Europe

By Adam Plowright and Germain Moyon in London