Chanting "Russia, Russia!" some 2,000 people in Montenegro have demonstrated against membership in NATO only days after the small Balkan country was invited to join the security alliance.

The protest Saturday was called by the pro-Russian opposition parties who are demanding that a referendum be held on the issue.

The Adriatic country of just over 600,000 people is split over membership in NATO because of traditionally close ties to Russia and because NATO bombed the country during the Kosovo war in 1999, while Montenegro was still part of a union with Serbia.

Protesters carried banners reading "NATO killers!" or "You Are Not Welcome Here." Former president Momir Bulatovic says "NATO invited us to have more soldiers against Russia."

He insisted "we must not participate in a NATO-Russia clash."