HONG KONG, Nov 18 (Reuters) – Dozens of protesters escaped from Hong Kong Polytechnic University on Monday on the back of motorbikes as police fired projectiles at them.

After sliding down a plastic hose from a pedestrian bridge they had been occupying on the university campus, the black-clad protesters were seen clambering onto waiting motorbikes and being driven away by supporters.

The protesters had to lower themselves about 30 feet onto the roadway below amid a hail of projectiles fired by police. Some of the motorcycles were waiting for them, while others sped to the scene.

Not everyone seems to have got away: A Reuters reporter later saw some of the motorbikes abandoned on the road, and a number of protesters appeared to have been arrested.

Many other protesters remained on the campus, which has been cordoned off by police using rubber bullets and tear gas to prevent them escaping and stop other protesters armed with Molotov cocktails breaking through the cordon to rescue them.

The past week has witnessed the most intense violence in five months of anti-government demonstrations in Hong Kong.

Demonstrators are angry at what they see as Chinese meddling in Hong Kong’s promised freedoms when the then British colony returned to Chinese rule in 1997. They say they are responding to excessive use of force by police.

China says it is committed to the “one country, two systems” formula granting Hong Kong autonomy. The city’s police deny accusations of brutality and say they show restraint.

(Reporting by James Pomfret, Writing by Timothy Heritage; Editing by Janet Lawrence)