At least 18 people are to stand trial over the construction of a building that collapsed three years ago in Bangladesh, killing nearly 1,130 people, mostly garment workers.

The April 2013 collapse of Rana Plaza in Dhaka ranks among the world's worst industrial accidents and prompted a global outcry for improved safety standards in the world's second-largest exporter of readymade garments.

At least 130 witnesses will get their first chance to give testimony when the trial of the accused of building violations gets under way on Tuesday.

Inside Story - Bangladesh: Sanctions for safety

It is alleged that three extra storeys were added to the six-floor structure.

The owner, Mohammad Sohel Rana, and former chief engineer are in custody, but at least five of the accused are on the run.

Al Jazeera's Tanvir Chowdhury, reporting from Dhaka, said the victims demand justice and expect the court speed the process. 

"The victims of the accident are saying that this case will run for years for all we know, knowing Bangladesh's justice system," he said.

"They say justice delayed is justice deinied.

"But we still have to see the outcome because Bangladesh does not have a good track record of bringing people to justice in any major industrial accident."

Hundreds more witnesses will tell their stories when 41 people appear on murder charges in a second trial in September.

The worst industrial disaster in Bangladeshi history put pressure on global brands such as Gap, JC Penney and Walmart which have their clothes made at low cost in Bangladesh.

'Not enough'

Some foreign firms have signed up to new agreements to improve workplace conditions.

But rights groups say not nearly enough has been done.

"In 2015 the workers get some money from the Trust fund but still from the manufacturers and the government they couldn't pay any compensation to the workers," Nazma Akther, the president of the combined Garment Workers Federation, told Al Jazeera.

"And now most of the injured workers rhey are severely injured and they need proper treatment and healthcare it is very absent and nobody takes care of them."

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Almost three in four survivors have not been able to work due to physical ailments and trauma.

Low labour costs and, critics say, shortcuts on safety, make Bangladesh the cheapest place to make large quantities of clothing.

Companies are split over how to improve conditions.

Big European firms signed an accord that would make them legally responsible for safety while US groups such as Wal-Mart Stores Inc have broken ties with non-compliant factories.

In 2013, the government raised the minimum wage for garment workers by 77 percent to $68 and amended its labour law to boost worker rights, including the freedom to form trade unions.

Source: Al Jazeera and agencies