Two suspected Syrians were arrested in Geneva on suspicion of transporting 'explosives and toxic gases' as part of a probe into a terror threat.

Switzerland's attorney general said the men were also suspected of making and hiding the dangerous materials.

But Geneva prosecutor Olivier Jornot today said only traces of explosives were found in the car, and did not elaborate on claims about potential chemical weapons.

More arrests are expected to be made in the coming days amid heightened security on Switzerland's border with France.

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Eyewitness Sharmila Berlin said she saw two men being arrested by police yesterday in the Geneva region

The two suspects are accused of the 'manufacture, concealment and transport of explosives and toxic gases', the federal prosecutor's office said in a statement

Mr Jornot said the two men, who spoke Arabic and had valid Syrian passports, had just arrived in Geneva.

They were subjected to extra checks because of their 'behaviour and their nationality', he added.

He also claimed the traces of explosives found in the car may not have been linked to the pair, who had only recently acquired the car.

Officials have opened criminal proceedings against the men under a law which bans groups such as al Qaeda and ISIS.

The men have been handed over to Swiss federal police despite denying criminal intent.

The two men are accused of the 'manufacture, concealment and transport of explosives and toxic gases', the federal prosecutor's office said in a statement.

Police were searching cars on the French-Swiss border following the raising of the terror alert yesterday

The Geneva region raised its alert level to three on a five-point scale on Thursday following fears of a potential terror attack

The news comes after it was revealed yesterday that Geneva police were searching for four suspects in relation to the deadly Paris attacks on 13 November

Both men were arrested yesterday on the road outside Cologny, a municipality in the canton of Geneva yesterday.

The city has remained on high alert due to an increased jihadist threat in Switzerland, with added security personnel making careful chats on vehicles.

Geneva's public prosecutor has announced a news conference for later today with no confirmation yet of the chemicals found in the car.

ISIS'S PLANS FOR CHEMICAL WARFARE ISIS has recruited experts with chemistry, physics and computer science degrees to wage war with weapons of mass destruction against the West, a shocking European Parliament report has claimed. The terror organisation, according to the briefing document, 'may be planning to try to use internationally banned weapons of mass destruction in future attacks'. The document, which was compiled in the aftermath of the deadly attacks on Paris claimed that ISIS has already smuggled WMD material into Europe. Experts fear that ISIS will be able to exploit a failure of EU governments to share information on possible terrorists. Already, British police forces have been conducting exercises on how to deal with various types of terrorist attack. But the EU report claims that government should 'consider publicly addressing the possibility of terrorist attack using chemical, biological, radiological or even nuclear materials'. The report, ISIL/Da'esh and 'non-conventional' weapons of terror warns: 'At present, European citizens are not seriously contemplating the possibility that extremist groups might use chemical, biological, radiological or nuclear (CBRN) materials during attacks in Europe. Under these circumstances, the impact of such an attack, should it occur, would be even more destabilising.' Rob Wainwright, head of Europol said after the attacks on Paris: 'We are dealing with a very serious, well-resourced, determined international terrorist organisation that is now active on the streets of Europe. 'This represents the most serious terrorist threat faced in Europe for 10 years.' Mr Wainwright warned that ISIS had serious capabilities in terms of resources and manpower.' Advertisement

The Geneva region raised its alert level to three on a five-point scale on Thursday following fears of a potential terror attack.

Armed police were deployed at sensitive locations across the city, which is home to the UN's European headquarters.

Swiss President Simonetta Sommaruga revealed yesterday that a 'foreign authority' had handed over intelligence information to Swiss intelligence about 'a potential IS cell in the Geneva area'.

Swiss intelligence service has been working closely with other US intelligence agencies in a bid to hunt down and prevent a possible terror attack in Switzerland

The western city has remained on high alert due to an increased jihadist threat in Switzerland, with added security personnel making careful chats on vehicles

The news comes after it was revealed yesterday that Geneva police were searching for four suspects in relation to the deadly Paris attacks on 13 November.

Mr Jornot said there is no indication these four suspects are still in Switzerland. He also said no link has been established between the quartet on the run and the arrest of two terror suspects today.

Swiss intelligence service has been working closely with other US intelligence agencies in a bid to hunt down and prevent a possible terror attack in Switzerland.