When a private sports club in an upmarket Dhaka neighbourhood "grabbed" a children's park for development this year, it sparked a wave of enraged protests rarely seen in impoverished Bangladesh.

Hundreds of parents, former national sports stars and environmental activists staged sit-ins for days, demanding the club hand back the park -- a green oasis for residents in one of the world's most densely populated and polluted cities.

"This is the lone ground for the area's kids. Yet the club grabbed it as if it was private property," former Bangladesh cricket captain Gazi Asharf Lipu, who joined the protests, told AFP.

The protests, which made front page news in Bangladesh, underlined the plight of Dhaka's millions of children, many of whom grow up without ever setting foot in a park.

The protests also highlighted the frustration of the city's ordinary residents whose precious patches of green space are routinely and illegally snatched by property developers, clubs and political parties for huge profits.

"It's a theft of public property. Yet, we are simply incapable of stopping these influential people," said Lipu, who led the Bangladesh team from 1985-1990.

In the 1970s, Lipu honed his skills at the sprawling park in Dhanmondi, where domestic cricket matches were regularly played, attracting thousands of spectators.

Officials estimate two-thirds of playing fields and other public spaces in Dhaka, a 400-year-old city, have disappeared -- developed into apartment blocks, mosques or become parking lots for lorries and dumping grounds for construction companies.

Once a Mughal outpost known for its lush parks and gardens, Dhaka has been transformed into a haphazard concrete jungle, following explosive economic growth -- and one of the world's worst cities to live in according to some studies.

The city's population has grown more than two and half times to 17 million in the last two decades. Residents are squeezed into an area of about 125 square miles (324 square kilometres), meaning a population density of around 120,000 persons per square mile.

Residents live in small apartment blocks, flanked by massive slums, while narrow roads are choked with cars, motorbikes and hundreds of thousands of three-wheel rickshaws.

Only 28 playgrounds and 70 parks exist in the city, "all very small in size" and most damaged and occupied in some way, according to Iqbal Habib, joint secretary of environment group Bangladesh Poribesh Bachao Andolon (BAPA).

"Even two decades back, there were hundreds of open spaces in Dhaka," he told AFP.

A lack of land means prices are at a premium, with a standard-sized flat in Dhaka's most upmarket neighbourhood of Baridhara costing about one million dollars.

"Public spaces became very lucrative to the grabbers when the city's rapid growth began in the late 80s and land prices went skyrocketing," said Akter Mahmud, professor of urban planning at Jahangirnagar University in Dhaka.

- Public anger growing -

BAPA has launched a series of protests against the "systematic" grabbing, which Habib said has attracted growing numbers of residents, fed up with a lack of government action and determined to fight back.

Lipu, who has set aside his business to campaign on the issue, has urged authorities to "declare a war" against the grabbers, warning the cricket-mad country that disappearing playing fields were even impacting on the national side.

"Even a decade ago, most of the national cricketers would come from the capital. Now you won't find a single player from Dhaka representing the national side."

"Lack of grounds mean Dhaka boys are now busy playing video games."

With the government so far seemingly indifferent to the protests and even accused of colluding with the grabbers, BAPA has also launched an array of court cases, although with limited success.

Bangladesh law prevents change of use of playgrounds, open spaces and parks, and no structure can be built on them.

In the bitter fight over Dhanmondi's park, the High Court ordered the sports club, which boasts influential businessmen as members, to stop harassing protesters, before authorities finally intervened in April and ordered the land handed back to residents.

Club president Manzur Kader told AFP some of its members "wrongfully" thought the space belonged to the club which wanted to expand.

- Psychological impact -

Studies show Dhaka has become one of the world's worst cities to live in, with alarming levels of pollution, unplanned urbanisation as well as ravaged public spaces.

Experts warn of the psychological impact of growing up without having anywhere to play outdoors or come together as a community.

"There will be catastrophic effects. So many children in Dhaka are growing up isolated, self-centred and emotionally vulnerable," Mahmudur Rahman, a Dhaka University psychology professor, told AFP.

"By playing with their friends, children learn social interaction, problem solving and leadership skills. They grow up with a feeling that they belong to a community, which is of their own," he said.

Khalid Ahmed, chief estate officer of Dhaka City Corporation, admitted many public spaces have been grabbed illegally.

He said his office was constantly fighting the grabbers, but it lacked the manpower to enforce the law. He called for a joint effort across all government agencies, including the police to protect them.

"Yes we've failed to protect some of the playgrounds and parks," Ahmed told AFP.

"We are doing our best to protect the remaining ones. (But) we can't do it alone."