Thousands took to the streets of Hong Kong on Sunday to protest against threats to press freedom in the city, days after a former newspaper editor was attacked with a cleaver in broad daylight.

Kevin Lau, former editor of the investigative Ming Pao newspaper, was left in a critical condition after Wednesday's brutal attack, seen as highlighting warnings from international watchdogs that the city's media independence is in jeopardy as Beijing seeks tighter control.

Organisers said that 13,000 people including journalists, activists and lawmakers marched in the swiftly organised rally, although police put the turnout lower at 8,600.

Protesters dressed in black waved banners declaring "They can't kill us all" as they condemned the vicious assault on Lau, urging police to solve the case quickly and saying journalists would not be swayed by violence.

"We need to tell the evil power that your knife is not going to deter us," Sham Yee-lan, chairwoman of the Hong Kong Journalists Association told reporters outside the government headquarters, before marching to the city's police department to deliver a petition with 30,000 signatures.

Ronan Chan, a 21-year-old journalism student, told AFP: "I still want to be a journalist. I won't be affected by the incident... A place without freedom of speech is not a civilised society."

Lau's condition improved on Saturday when he was transferred out of an intensive hospital unit to a private ward, greeting journalists with a defiant hand gesture.

A recorded sound clip by Lau played through loudspeakers at the rally declared: "Violence wants us to be afraid. If we are afraid, we will lose freedom. I hope all journalists believe there is justice."

"People should not take freedom for granted. We cannot assume it will never change. It takes everyone to guard it," he was heard to say.

The attack on Lau provoked shock in a city known for its safety, leading Hong Kong's leader, Chief Executive Leung Chun-ying, to stress that freedom of speech will be protected in the financial hub.

- Leung's daughter sparks row -

But one of Leung's daughters, Leung Chai-yan, sparked an online row after voicing doubt over the attackers' motive, according to South China Morning Post.

"What does the attack have anything to do with press freedom?! Come on people", she wrote on her Facebook page, drawing criticisms from netizens who accused her of cold blooded comments.

A police investigation into the incident is underway but no arrests have been made so far in what authorities called a "triad-style" attack.

A similar march held the previous week prior to Lau's attack drew 6,000 people protesting at several high-profile incidents seen as aimed at stifling the free press, including the removal of Lau as editor of the liberal Ming Pao, allegedly for being unsympathetic to Beijing. Police put the count for that march at 1,600.

Earlier this month the international Committee to Protect Journalists said media freedom in Hong Kong was "at a low point", citing self-censorship among reporters, financial and physical threats against the media and legislative steps that could hinder investigative reporting.

Paris-based Reporters Without Borders also said in a report that Hong Kong's media independence was "in jeopardy", as China flexes its muscles to stifle critical coverage.

Certain pro-Beijing lawmakers also attended Sunday's rally, local broadcaster Radio Television Hong Kong reported.

Lawmaker Chiang Lai-wan was quoted by the broadcaster as saying that violence against journalists cannot be tolerated regardless of political ideals.

Tycoon Li backs press freedom after attack on Hong Kong editor
Hong Kong (AFP) Feb 28, 2014 - Influential Hong Kong tycoon Li Ka-shing on Friday condemned a brutal attack on a veteran journalist and warned the territory will suffer serious harm if it loses press freedom.

Li, who is Asia's richest person, joined a chorus of dismay over Wednesday's attack on Kevin Lau, who is being treated in hospital after being hacked with a cleaver in broad daylight.

A new alliance of journalist and news organisations plans to stage a rally Sunday to condemn a string of violent attacks against the media which have stoked concerns for freedom of expression in the southern Chinese city.

"Violence can in no way be right. No matter what, the rule of law is the most important (aspect) in Hong Kong. Hong Kong is nothing without rule of law," Li said at a press conference held as his conglomerate Hutchison Whampoa announced financial results.

Appearing solemn and concerned, he said press freedom "is our core value. If Hong Kong does not have press freedom, Hong Kong will face huge losses."

Li, an 85-year-old self-made figure who is worth $32 billion and rarely comments on political matters, is considered pro-Beijing and has criticised pro-democracy campaigns in the past.

The attack on Lau, former editor of the liberal Ming Pao newspaper, has drawn condemnation from the United States and the European Union, as fears grow that Beijing is tightening its grip 17 years after the city was handed over from Britain to China.

Lau was removed as editor at the Ming Pao daily last month, triggering protests by staff who feared that replacing him with an editor from Malaysia seen as pro-Beijing was an attempt to stifle the paper's strong track record of investigative reporting.

Authorities said Friday that Lau, who was left fighting for his life with multiple deep wounds, is slowly improving and has regained consciousness.

"His situation has improved from critical to serious this morning," a government spokesman told AFP.

An investigation is under way to track down the perpetrators. The South China Morning Post said Friday that anti-triad detectives were tapping their networks of "snitches" associated with the crime gangs for leads.

"Every information on the payroll is being tapped for information. No stone is being left unturned," the paper quoted an unnamed police source as saying.