SKOPJE (Reuters) - Police in North Macedonia raided several locations on Friday to prevent a potential attack organized by the supporters of the Islamic State, the Interior Ministry said in a statement.

The ministry said it launched the operation after exchanging information with a “partner country”, without identifying the country.

Items and devices linked to a possible attack were seized, the ministry said, without giving further details.

The U.S. Embassy in Skopje also issued a security alert to its citizens traveling to North Macedonia on Friday warning of “a heightened risk of terrorist attacks inspired by extremist ideology in North Macedonia”.

The majority of North Macedonia’s 2 million population is Orthodox Christian, with Muslims accounting for around 35 percent of the total population.

Authorities in the former Yugoslav republic estimate as many as 130 of its citizens have fought or are currently fighting alongside Islamist groups in Syria and Iraq.

In 2016 a court sentenced six people, including an imam, to up to seven years in prison each for joining the fight or recruiting others.

Last week North Macedonia signed accession protocol with NATO and is expected to become its 30th member sate once all it is ratified by all member states.