Switzerland's Attorney General's office and the Swiss Federal Police Office say they have opened criminal proceedings against two Syrian citizens on suspicion they manufactured, concealed and transported explosives and toxic gases and also allegedly violated bans on militants groups like al-Qaida and Islamic State.

The attorney general said in a statement the two people, who were not further identified, were arrested Friday in the Geneva area.

It was not immediately clear Saturday if the two had any connection with the four suspects with alleged ties to the extremist Islamic State group that Geneva authorities have been searching for.

Local authorities were to provide further details in a press conference later Saturday.