A court in Bangladesh has formally charged 38 people with murder in connection with the 2013 collapse of the Rana Plaza building which killed 1,135 people in the country’s worst industrial disaster.

A total of 41 defendants face charges over the collapse of the complex, which housed five garment factories supplying global brands. Plaza owner Sohel Rana is the principal accused.

Public prosecutor Abdul Mannan said 38 people had been charged with murder while three were charged with helping Rana to flee after the incident. Rana was arrested after a four-day manhunt, apparently trying to flee across the border to India.

The scene after the Rana Plaza collapse in April 2013. Photograph: Munir Uz Zaman/AFP/Getty Images

Of the 41 people charged, 35, including Rana, appeared before the court and pleaded not guilty, Mannan told reporters. The other six are fugitives and will be tried in absentia.

If convicted, defendants could face the death penalty.

The collapse of the complex, built on swampy ground outside the capital Dhaka, sparked demands for greater safety in the world’s second-largest exporter of readymade garments and put pressure on companies buying clothing from Bangladesh to act.

Duty-free access to western markets and low wages for its workers helped turn Bangladesh’s garment exports into a $28bn-a-year industry that is the economic lifeblood of the country of 160 million people.

The minimum monthly wage for garment workers in Bangladesh is $68, compared with about $280 in mainland China, which remains the world’s biggest clothes exporter.

The Rana Plaza tragedy prompted safety checks that led to many factory closures and the loss of exports and jobs, but the industry had begun to recover strongly despite sporadic attacks in Bangladesh claimed by Islamic State and al-Qaida. These have included murders of liberals, gay people, foreigners and members of religious minorities.

But a targeted attack on a restaurant in Dhaka on 1 July that claimed the lives of 20 people including 18 foreigners, many of whom worked in the garment business, could pose a fresh threat to the industry.

Islamic State said it was responsible for one of the most brazen attacks in the south Asian nation’s history, although that claim has yet to be confirmed.