Hong Kong is pondering whether to rip out some seats from overcrowded metro trains to give the city's smartphone-addicted population more room to interact with their devices.

The transport and housing bureau has suggested that the MTR Corporation, which operates the underground railway system, consider the move to relieve rush-hour congestion.

"There are an increasing number of passengers reading newspapers or using mobile devices such as tablet computers or smartphones during their trips that require more personal space on trains," it said in a paper to the legislature Tuesday.

It recommended the "removal of some seats in some train compartments, to increase carrying capacity" as well as incentives for passengers who travel outside peak hours.

Smartphone penetration stands at 87 percent of the city's residents, according to government figures from September 2013. Authorities have been forced to plaster MTR stations with signs warning passengers to look up from their phones to avoid injury on escalators.

The train carriages were designed in the 1980s and 1990s to hold a maximum six people in one square metre (10.7 sq ft) of space. The bureau has proposed reducing this number to four to give passengers more space.

Commuters were "less willing to board a train that looks crowded even when there is still room available", it said. "They prefer waiting for the next train."

On a weekday, an average of 5.2 million passenger trips are made on the 218-kilometre (135-mile) network.

Kenneth Chan Chi-yuk, chairman of the Elderly Services Association of Hong Kong, criticised the plan.

"There are more elderly people now (in Hong Kong) and public facilities are not adequate," he said.

"Does it not contradict the original purpose of having seats?"