Protesting students from New York's Columbia University -- a centre of the campus unrest currently sweeping the United States -- disrupted rush hour traffic and skirmished briefly with police during demonstrations yesterday (Wednesday).

About 550 Columbia students marched onto a four-lane highway, parading placards that condemned U.S. intervention in Cambodia and the Kent University student killings.

After arguing with drivers -- some of them bound for hospitals -- the students agreed to clear the highway and the rush hour traffic started to flow again.

One group of students wanted to block traffic on the main George Washington Bridge between Manhattan and suburban New Jersey.

Then came police action. The police formed a skirmish line and charged the protesting student. After a few arrests the demonstration broke up without major violence.

Columbia University has been a centre for student strike action. The night before the road-block demonstration, a Columbia contingent marched New York streets to join City College students in taking over a college building.