Swiss officials have confirmed the arrest of two people of Syrian origin as part of a probe into a terror threat.
In a statement, Switzerland's Attorney General said the two people were arrested in Geneva Friday on suspicion of making, hiding and transporting explosive and toxic gases.
The statement said criminal proceedings have been opened against the two under a law prohibiting terrorist groups such as al-Qaida and Islamic State.
Traces of explosives were found in the suspects' vehicle when they were arrested, according to Swiss media.
Authorities in the Geneva region had been searching for four suspected jihadists with alleged ties to the Islamic State group, but police have not said whether Friday's arrests were connected to the search.
No details were provided on where their car was stopped.
Swiss police increased the terror alert level in Geneva Thursday. Authorities said they were acting on information from Swiss federal officials that “suspicious individuals" believed to be connected to last month's Paris terrorist attacks "could be in Geneva or the Geneva region."
France’s neighboring countries have tightened their security measures since the Paris attacks, which left 130 people dead and more than 350 injured. The Islamic State militant group claimed responsibility.
One suspect linked to the attacks is still at large.