The heads of nine universities in Hong Kong have criticised the government for its “ineffective” response to the political unrest that moved to the city’s campuses this week.

A statement signed by presidents of some of the region’s top academic institutions said Hong Kong had seen a rapid escalation of violence in the last week, including the deaths of two people . Several universities were now under protesters’ control, the statement said.

“It is regrettable that societal disagreement has led to university campuses becoming major political battlefields, and that the government response has so far not been effective … The government must take the lead with swift and concrete action to resolve this political deadlock and to restore safety and public order now,” it said.

Economic data on Friday confirmed that Hong Kong had entered its first recession in a decade as tourist numbers and retail sales fell.

Since Tuesday protesters have turned several university campuses into fortresses, digging up bricks to build blockades, setting up checkpoints and stockpiling food, protective equipment and weapons.

At the Chinese University of Hong Kong (CUHK), the site of an hours-long battle between riot police and protesters on Tuesday night, demonstrators left boxes of molotov cocktails on a bridge overlooking a main highway they had blocked.

Protesters operated checkpoints at the school’s entrances, checking IDs and in some cases searching bags. Some with plastic shields and handsaws patrolled with walkie-talkies. A helicopter circled overhead, which protesters claimed had been sent by police to monitor their positions.

The vice-chancellor of CUHK, Rocky Tuan, who signed the statement, threatened to call in “assistance” if demonstrators did not leave the campus. “Our campus has been occupied by masked protesters, including those from outside. The situation is out of control and unacceptable,” he said in a separate open letter.

After more than five months, Hong Kong’s most severe political crisis since its return to China in 1997 reached a new peak this week following the death of a demonstrator last Friday.

On Monday a police officer shot an activist in the torso with a live bullet, and a man was set on fire while arguing with protesters. On Thursday a man died after being hit on the head during a clash between protesters and pro-Beijing residents.

Rocky Tuan, the vice-chancellor and president of the Chinese University of Hong Kong. Photograph: Philip Fong/AFP via Getty Images

Protesters and residents have responded emotionally to what they see as the government’s attack on Hong Kong’s universities and intellectual freedom.

When police stormed CUHK and later rained down more than 2,000 rounds of teargas and rubber bullets on a bridge occupied by protesters, former students and others said they were reminded of Beijing’s crackdown on student pro-democracy demonstrators in 1989.

“I was so scared,” said Olivia Kong, 28, a a previous CUHK student who has spent the last three days on campus, sleeping in empty school buildings and helping source water, first aid and other supplies. “Attacking the universities is very significant, with Beijing’s history of killing students.”

On Friday many protesters were leaving CUHK for home or other universities where police action was expected. After four days of occupation, in a movement that has prided itself on its fluidity, divisions had begun to show as a group argued over whether to stay or go.

Earlier, a group of protesters cleared a highway they had blocked since Monday as a gesture of goodwill, only to blockade it again in the early evening. When riot police arrived, most protesters retreated and dozens of volunteer drivers arrived to ferry protesters away.

Protesters had demanded that local district elections, scheduled for 24 November, should go ahead. Hong Kong’s chief secretary, Matthew Cheung, said the government was preparing for the elections but did not promise they would be held. Some believe the government is angling to postpone or cancel the elections in expectation of major losses.

Hundreds of people rallied in lunchtime protests across the city on Friday, the fifth day that office workers and other residents have joined weekday demonstrations and disrupted traffic. Protests have previously been during the weekend or in the evenings.

Demonstrators raise their hands during a protest in the financial district in Hong Kong. Photograph: Achmad Ibrahim/AP

“Every day, every single day, there are more instances that keep us coming out. This is us telling the government we want this to stop,” said Margaret, 55, who works in investment management and was attending a demonstration in Central, a business district, where riot police have teargassed those who have turned up over the last four days.

“They are supposed to be protecting us. Instead they are doing the opposite,” she said. “I don’t know how much worse it can get.”

Others said they were frustrated by the escalation in tensions this week. “The teenagers are out there are risking their lives for Hong Kong,” said Sam Ho, an accountant. “I just feel like this is not the same place as before. This is a police state where the police can do whatever they want.”

In the evening, police fired teargas at demonstrators in Mong Kok, in Kowloon, where protesters set a barricade alight that erupted in explosions before firefighters put the blaze out. Hong Kong’s hospital authority said 14 people were treated in hospital for protest-related injuries on Friday.

The protests have attracted international attention, causing friction with Beijing.

On Thursday a US congressional advisory body called on lawmakers to enact legislation that would strip Hong Kong of its special economic status granted under US law if the Chinese military were deployed to crush the protests.

In Taiwan, civic and religious groups protested outside Hong Kong’s representative office, calling for an end to what they said were abuses against anti-government protesters in the territory.

In London, Hong Kong’s justice minister, Teresa Cheng, said she was injured by protesters when attending an event on Thursday night. Video showed protesters surrounding Cheng and yelling “Shame on you”. At one point the cabinet official was seen falling.

Beijing accused the UK, which has backed the right of Hong Kongers to express their views, of fuelling unrest in the city.

A foreign ministry spokesman, Geng Shuang, said at a regular press briefing: “If the British side does not change its wrong practices, and continues to add fuel to the fire … then it will bring calamity on itself.”﻿