The police arrived in force at dawn on Saturday, with orders to clear "infiltrators" from the Gaza war protest camp at Northeastern University in Boston.

Within an hour, more than 100 people were under arrest, students and non-students alike, and many of their tents flattened or removed.

A large counter-protest then formed, as officers from the state police in tactical gear hauled off their suspects. The scene was one of confrontation, and chaos.

Northeastern campus administrators said they were compelled to call police as infiltration by outsiders "led to a clear escalation in tensions" and that an antisemitic slur had been heard - something the protesters deny.

As the campus protests stretch into a second week across the US, Northeastern is among many colleges that have now taken the decision to crack down hard and refused calls to divest from companies involved in Israel's military.

Columbia in New York squashed the very first camp on 18 April, citing "a harassing and intimidating environment for many of our students". Since then they have blanked protester demands and announced suspensions for some students.

The student response has been escalation, and on Tuesday dozens occupied and damaged a university building, leading to officials threatening expulsions. On Tuesday night, police moved onto campus in force at the university's request to end the occupation.

Other colleges, however, have shown that confrontation, chaos and escalation can be avoided.