Media playback is unsupported on your device Media caption Police fired teargas and rubber bullets at protesters, who are angry at poor safety standards in factories

Hundreds of people are still missing after Wednesday's collapse of a building in Bangladesh which killed over 300 people, local officials say.

More than 40 people have been rescued since Thursday from the Rana Plaza building near Dhaka, which housed clothes factories.

Prime Minister Sheikh Hasina has called for special prayers to be held across the country later for the victims.

Angry protesters have taken to the streets of Dhaka for a second day.

They are demanding the authorities arrest the owner of the collapsed building and improve conditions for garment workers.

Police said that at least 10,000 people had gathered for the demonstrations and described the situation as "volatile".

Police used tear-gas and rubber bullets to break up the crowds, which had blocked roads, torched buses and attacked textile factories.

Bangladesh media reaction The Daily Sun asks: "Have the garment factories become a death valley for poor workers?". It says the sense of impunity around such disasters has left factory owners with "the feeling they can get away with... every violation of the basic rules of workers' safety and are accountable to nobody". The New Age also pulls no punches, saying it is a "clear case of mass murder committed by greedy rich people" and accuses the government of protecting such people "by making misleading public statements". The Holiday points out that factory owners owe their opulent lifestyles to some 3.5 million workers, mostly women, whose lives are "wretched". "The accumulation of wealth should not be at the cost of exploitation," it says. The Daily Star praises people's reaction to the disaster and hopes that "when the dust has settled and the rubble cleared... the authorities will get their act together in addressing loopholes in the system that allow for disasters like this to happen".

The owner of the building, according to police, ignored warnings about cracks appearing earlier this week. He is said to be in hiding, but Sheikh Hasina has promised that he will be punished.

'Non-stop efforts'

Some 2,000 people were in the Rana Plaza building in Savar when it collapsed suddenly on Wednesday morning.

Teams from the army, the fire service and border guards are still working around the clock at the site to find survivors, using heavy lifting gear, tools and their bare hands.

A military official, Maj Gen Chowdhury Hasan Suhrawardy, told AP that search and rescue operations would continue until at least Saturday.

"We know a human being can survive for up to 72 hours in this situation. So our efforts will continue non-stop,'' he said.

Search teams have been dropping water bottles and food items to other survivors who are still trapped.

The local command centre said families had given the names of 372 people who were still unaccounted for.

However, reports suggest the number of missing is much higher.

The number of people confirmed dead now stands at 302.

One trapped man, Mohammad Altab, was able to speak to journalists on Thursday, saying: "I want to live. It's so painful here."

Media playback is unsupported on your device Media caption A police safety team filmed footage of cracks in the building the day before the collapse

Another man, trapped deeper in the rubble, begged for rescue, said: "It's hard to remain alive here. It would have been better to die than enduring such pain to live on."

Local hospitals have been overwhelmed with the arrival of more than 1,000 injured people.

Media playback is unsupported on your device Media caption Are London shoppers concerned about where their clothes come from?

Bangladesh has one of the largest garment industries in the world, providing cheap clothing for major Western retailers which benefit from its widespread low-cost labour.

But the industry has been widely criticised for its low pay and limited rights given to workers and for the often dangerous working conditions in garment factories.

Primark, a clothes retailer with a large presence in Britain, confirmed that one of its suppliers was on the second floor of the Rana Plaza, and said it would work with other retailers to review standards.

US discount giant Wal-Mart said it was still trying to establish whether its goods were being produced at the Rana Plaza.

Labour rights groups say the companies have a moral duty to ensure their suppliers are providing safe conditions for their employees.

"These are billion dollar companies. They have a huge amount of power to change the way that building safety is accepted here," Gareth Price-Jones, Oxfam's country director for Bangladesh, told Reuters.