A group of 17 suspected illegal immigrants from Vietnam have been arrested after they were found travelling in the back of a lorry on the motorway.

The vehicle was stopped by police after a passing motorist grew suspicious and called 999 while driving on the M25 in Hertfordshire yesterday.

After officers flagged down the lorry on the M1 near St Albans, all 17 Vietnamese men travelling in the back were taken into custody.

The Polish driver was also arrested on suspicion of assisting illegal entry into the UK.

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Found: A group of 17 suspected illegal immigrants were discovered in the back of a lorry in Hertfordshire

Arrest: Officers arrested the Polish lorry driver after flagging down the vehicle on the M1 near St Albans

All but two of the migrants claim to be underage, meaning that after having their age assessed they will be taken into the care of social services rather than deported immediately.

The lorry driver could face a fine of £36,000 - up to £2,000 for each migrant - if he is found to have been responsible for bringing them into the country.

A spokesman for Hertfordshire Police said: 'Police were called shortly after 4pm on August 8 following reports of suspicious activity on a lorry on the M25 in Hertfordshire.

'The member of the public who made the call followed the lorry which made its way on to the M1 before police stopped it close to Junction 9 of the M1.

'Eighteen people who are believed to have entered the UK illegally on the lorry were taken into custody for their safety.

'The driver of the lorry, a 40-year-old man from Poland, has been arrested on suspicion of assisting people entering the UK unlawfully.'

Discovery: The lorry was intercepted near junction 9 of the M1 after coming off the M25

Queues: Migrants waiting for food hand-outs at the 'Jungle' refugee camp in Calais

Charity: A humanitarian organisation is giving out packages to migrants who have no other means of support

The incident comes after weeks of mounting tension at Calais as thousands of would-be migrants have attempted to enter Britain via the Channel Tunnel.

Aided by a series of wildcat strikes by French ferry workers, the asylum seekers have tried to hitch a lift with lorry drivers and even holidaymakers.

One migrant walked all the way through the Tunnel earlier this week - despite the extreme danger of making the crossing while trains speed between Britain and France.

Today hundreds of migrants stormed a main road, attempting to clamber on to lorries in front of stunned holidaymakers.

The huge group dashed for the busy road that runs alongside the 'New Jungle' migrant camp after noticing that traffic had ground to a halt.

Camp: The Jungle is currently home to several thousand immigrants who hope to reach the UK

Protest: Immigrants and activists staged a march in Calais yesterday calling for the UK to open the border

IMMIGRANTS ARE JUST LIKE BRITS ON HOLIDAY, SAYS UN ENVOY A UN envoy has sparked outrage by comparing Calais migrants to westerners enjoying a holiday in Thailand and accusing Britain of 'racism' for trying to control the flow of immigration. François Crépeau, a 'special rapporteur' on the human rights of migrants, claimed that migrants 'with darker skin colours' faced more public opposition than white Europeans. He told the Sunday Times: 'It is remarkable that in most of our countries we have nothing against numerous Germans and French coming in and we dislike profoundly that people with darker skin colours are coming in. 'So there are elements of racism in this nationalist, populist reaction to migration.' Mr Crépeau, a Canadian legal academic, added: 'It is not an invasion. It is called mobility. It goes with globalisation. That is what we do when we go for vacation in Thailand.' He also claimed that the UK authorities were encouraging people-smuggling gangs by closing off legal routes to immigration. Tory MP Andrew Percy said: 'It is disgusting to call British people racist for simply wanting to do what every other country does in the world, which is defend its border and protect people in other countries by cutting off a route which means they have to put their lives at risk.' Advertisement

The migrants pounced upon a security lapse after police officers who usually guard the entrance to the road left their post.

As cars and lorries sat stationary, the group of around 300 migrants desperately opened lorry doors with some succeeding in climbing inside. Others threw bollards under vehicles to stop them from continuing along the road that leads to the ferry port.

A large group of migrants ran along the busy road as police arrived and threatened to spray them with teargas before the migrants were eventually returned to the camp.

The authorities have recently moved to tighten up security at the port, but critics insist they will be unable to stem the flow of migrants from war zones and dictatorships such as Syria, Afghanistan and Eritrea.

It has emerged that 100 elite British troops have been stationed in Kent in order to respond to the possibility of a terror attack amidst the chaos.

The Special Forces Support Group, normally based in Wales, is now at a barracks in Folkestone after officials became alarmed by how easily migrants have been able to make it across the Channel.

Defence chiefs fear that ISIS-inspired terrorists will take advantage of the anarchy at Calais to carry out an assault in Britain.

Troops from the Special Reconnaissance Regiment are believed to be monitoring asylum seekers on both sides of the channel to ensure they are not infiltrated by jihadists.

Desperate: Migrants on the tracks of the Channel Tunnel hoping to make it across to Britain

Foreign Secretary Philip Hammond today warned that the surge of migrants travelling from Africa to Europe could undermine living standards and social stability in the EU.

He suggested that many migrants know they will never be forced to leave Europe once they arrive and called for a stronger mechanism to eject bogus asylum seekers.

'As long as the Europe Union's laws are the way they are, many of them will only have to set foot in Europe to be pretty confident that they will never be returned to their country of origin,' Mr Hammond said during a visit to Singapore.

'Now, that is not a sustainable situation because Europe can't protect itself and preserve its standard of living and social structure, if it has to absorb millions of migrants from Africa.'

The Foreign Secretary insisted that security at Calais would not provide a long-term solution to the crisis and pledged to co-operate with the French to tackle the 'root cause'.

'Having reviewed the situation in the light of the crisis it is clear that there is more that can be done to enhance the physical security of the Tunnel,' he said.