UPDATE 11-Hong Kong universities become 'battlefields' as citywide violence spreads

* Fierce battle rages at Chinese University in New Territories

* Democratic opposition condemns police "battlefield"

* Tear gas again in Central after extreme day of violence

* Police say protesters have committed "insane" acts

* (Recasts with university clashes, adds details of latest flare-ups, comments by protester and officials, other details)

By Jessie Pang and Josh Smith

HONG KONG, Nov 13 (Reuters) - Police in Hong Kong battled pro-democracy protesters at several university campuses in sometimes savage clashes, as parts of the city were paralysed including Hong Kong's Central financial district that was tear-gassed for a second day running.

The flare-ups occurred a day after police shot an unarmed protester at close range and a man was doused with petrol and set on fire in some of the worst violence since the protests began nearly five months ago in the China-ruled city.

At the rural Chinese University near Tai Po, some of the fiercest fighting broke out at night as riot police stormed the campus where hundreds of protesters congregated, firing a barrage of tear gas, rubber bullets and water cannon.

Hundreds of masked protesters, many of them students, hurled back petrol bombs, rocks and bricks, some launched with catapults. After the clashes, dozens of the injured lay sprawled on the ground at a nearby sports pitch.

The chaotic night scenes of explosions, smoke plumes, yelling and sustained gunfire, which left scores of injured students sprawled on the ground, stoked a sense of dread among some who recalled the 1989 Tiananmen Square crackdown by Chinese troops on pro-democracy protesters in Beijing.

"The fear among the students is so strong," said Wing Long, a 25-year-old theology student. "That's why we've gathered today to stop it from happening."

The police, however, said protesters in the campus had thrown debris and petrol bombs onto a nearby highway linking the Northern New Territories with Kowloon, bringing traffic to a standstill in a haze of tear gas smoke.

The city's 24 pro-democracy lawmakers condemned the police in a joint statement, saying the nonstop firing of tear gas had turned the campus into a "battlefield," while urging the international community to speak out for Hong Kong's youngsters to "prevent the recurrence of the tragedy of 1989."

Medics on the scene told Reuters that at least 60 people were injured.

At City University, students in hard hats and gas masks had spent much of the day barricading the campus, making home-made shields, and stockpiled bricks and petrol bombs on bridges and other approaches.