Hong Kong leader Carrie Lam acknowledged on Tuesday that the record turnout in local elections won by pro-democracy candidates highlighted dissatisfaction with her administration, while appealing for an end to violent protests.

Appearing tired and drawn, Lam spoke a day after results showed democratic candidates secured almost 90 per cent of 452 district council seats in Sunday's elections, a landslide victory in polls that were widely seen as a barometer of the opposition to the Beijing-backed politician following months of unrest.

China, which has blamed foreign forces for fomenting unrest in the city, has not directly commented on the results, and major news outlets among China's tightly controlled media largely avoided detailed reporting of how Hong Kongers voted.

On Tuesday, top diplomat Yang Jiechi condemned the passing of U.S legislation supporting protesters, saying China had "expressed our severe position the American side," according to state news agency Xinhua.

A day earlier, the foreign ministry summoned U.S. Ambassador Terry Branstad to protest the Hong Kong Human Rights and Democracy Act, which it said amounted to interference in an internal Chinese matter.

WATCH: Hong Kong leader Carrie Lam responds to election results

Hong Kong leader Carrie Lam acknowledged on Tuesday that the record number of voters in district elections highlighted dissatisfaction with the government as she thanked residents for voting peacefully despite a relatively volatile environment. 1:55

Lam, Hong Kong's most unpopular post-colonial leader, acknowledged voters in the city wanted to express their views on many issues, including "deficiencies in governance."

Speaking in measured tones, she thanked residents for voting peacefully and hoped the calm weekend was not just for the elections but a signal that residents want an end to unrest that has rocked the Chinese-ruled city for six months.

"Everybody wants to go back to their normal life and this requires the concerted efforts of every one of us," Lam said during her weekly address at the government's headquarters.

"So, as I have said repeatedly, resorting to violence will not give us that way forward. So please, please help us to maintain the relative calm and peace... and provide a good basis for Hong Kong to move forward."

Lull in violence

The Asian financial centre has enjoyed a rare lull in violence for nearly a week, breaking from six months of often violent anti-government unrest that has plunged the city into its biggest political crisis in decades, creating the greatest internal challenge yet faced by China's President Xi Jinping.

The Chinese leadership has set up a crisis command centre on the mainland side of the border and is considering replacing its official liaison to the restive semi-autonomous city, people familiar with the matter said.

People gather in support of pro-democracy protesters during a lunch break rally in the Kowloon Bay area in Hong Kong on Tuesday. (Nicolas Asfouri/AFP via Getty Images)

Protests have sprung up on an almost daily basis since June, with flash mobs often gathering with little or no notice, at times forcing the government, businesses, schools and even the city's international airport to close.

The violence had escalated up to last week, with protesters hurling petrol bombs and firing arrows at police who responded with tear gas and rubber bullets.

Demonstrators are angry at what they see as Chinese meddling in the freedoms promised to the former British colony when it returned to Chinese rule in 1997.

China denies interfering and says it is committed to the "one country, two systems" formula put in place at that time. Police say they have shown restraint in the face of potentially deadly attacks.

University standoff

While calm has descended across most of the city, a small group of protesters remain holed up in Polytechnic University, surrounded by police following extreme clashes at the campus on Kowloon peninsula in the run-up to elections.

In her speech Lam urged them to leave peacefully as soon as possible.

On Tuesday, university staff combed the sprawling campus looking for holdouts, finding one female protester, Professor Ping-kong Alexander Wai told reporters.

A team including management, security guards, councillors and the Hong Kong Red Cross, search rooms for any remaining protesters hiding at PolyU on Tuesday. (Anthony Wallace/AFP via Getty Images)

The Cross-Harbour Tunnel, a major artery linking Hong Kong island to the Kowloon peninsula which closed after protesters occupied the campus nearby, will re-open at 5 a.m. local time on Wednesday, chief secretary Matthew Cheung said.

Government staff and contractors spent days cleaning the area, which he said was left looking like a "war-zone," with fire hydrants and toll booths destroyed.

The anti-government demonstrations bolstered support for democrats in Sunday's elections, with a record three million people casting their vote.

The pro-democracy parties overwhelming victory poses a conundrum for Beijing and piles pressure on Lam, who is facing renewed calls to step down. The democrats took control of 17 out of 18 district councils.

Some observers say Lam, who came to power in 2017 on a platform to heal social divisions, is out of touch with the population and won't say anything concrete unless Beijing gives her the green light.

"There's no content in her talk, which is usual," said Ma Ngok, political scientist at Chinese University of Hong Kong.

"The majority of the people still support the [pro-democracy] movement so it is up to [Beijing] to respond. If they don't respond with any kind of concessions, I think the protests would go on for some time."