Shanghai sprung back to life on Wednesday after two months of bitter isolation under a ruthless COVID-19 lockdown, with people driving cars again or cramming into trains and buses to go back to work, hoping to never go through a similar ordeal again.

The 25 million residents in China's largest and mostcosmopolitan city endured two months of frustration, mental stress and economic loss, as the country went against the global consensus that COVID cannot be decisively defeated and imposed a zero-tolerance policy to stamp out outbreaks.

"I feel like I've regained my freedom," university student Hang Meichen said.

Joggers, skaters and dog walkers defied the muggy heat to take over riverfront parks. Shopkeepers were cleaning windows. Men in buttoned down shirts walked into flashy office towers, but not in the same numbers as before the outbreak, with many firms enforcing a staggered return to work.

Life was not fully back to the pre-COVID normal. Restaurant dining remains banned, shops can operate at only 75% capacity and gyms will reopen later.

There were also long queues at testing sites, with residents needing recent negative results to take public transport and enter various buildings, and many queued at vaccination centres.

The fear that COVID - and with it, strict restrictions on social life - can return was visible. Police and clerks at public-facing desks were wearing full hazmat suits. Many commuters wore gloves and face shields. All wore masks.

Another Shanghai resident, surnamed Dong, was drinking beer with a friend in the city's former French Concession neighbourhood, but he was not in a celebratory mood.

"It's not like the happiness you feel when you welcome the New Year, because this isn't a good thing," she said. "It's very complicated. The last two months have not been easy for anyone."

"I'm happy because I can see my friend, but when I was alone I really wanted to cry"."

Businesses were also having mixed feelings about their outlook after the lockdown, which battered Shanghai's manufacturing and export sectors, disrupted supply chains in China, the world's second largest economy, and elsewhere and slowed international trade.

China's factory activity shrank less sharply in May as some production resumed, but it was still the second-sharpest monthly slump since February 2020, in the initial stages of the COVID pandemic.

Many analysts expect the Chinese economy to contract in the second quarter, and the recovery to be a grinding process heavily dependent on COVID developments, with consumers and businesses unlikely to regain confidence immediately.

But some consumption was noticeable.

People took to reopened shops to buy fresh fruit and vegetables and other products they craved during the lockdown when they could not always order everything they wanted, relying heavily on group orders of basic supplies with neighbours.

"I bought some soy beans, this was not possible to buy through group-buys, some broccoli, and some prawns," said a woman surnamed Wang as she pushed a bicycle laden with groceries.

"This is my first day out."

Some were buying mugwort leaves, which in China people hang on their doors for the Dragon Boat Festival holiday, which begins on Friday, to keep evil away.

Some people believe they also help deter mosquitoes and termites, which have proliferated in parts of the city as authorities struggled to maintain basic services such as trash collection and disinfection spraying.

The city's handling of the lockdown provoked rare protests, with people at times banging pots and pans outside their windows to show discontent. Those were awkward scenes for the ruling Communist Party in a sensitive year when President Xi Jinping is expected to secure a precedent-breaking third leadership term.

Shanghai's government published what it called a "thank you" letter to residents, with medical staff, police, the army, journalists and "grass-roots" cadres among many getting special mention for their contributions.

"Under the strong leadership of the Communist Party's Central Committee with Comrade Xi Jinping at the core, after more than two months of continuous fighting, the arduous battle to defend Shanghai has achieved a major milestone," it said.

"This is a moment everyone has been waiting for... we would like to thank all Shanghai citizens in particular for their support and dedication!"

On social media, some users responded to the letter with victorious celebrations, while others demanded a letter of apology instead.

"Shouldn't those who wield great power and can arbitrarily inflict harm on others be held accountable?" one user commented.

On Tuesday, Shanghai's largest quarantine facility - a50,000-bed section of the National Exhibition & ConventionCenter - discharged the last two of the 174,308 COVID-positivecases who had been housed there. It declared itself shut.

But Shanghai's lockdown ordeal has come to symbolise what critics say is the unsustainability of China's adherence to a zero-COVID policy.