Labour rights groups have stepped up their calls for retailers and brands buying apparel from Bangladesh to take steps to ensure the safety of workers making their clothes.

Their demands have taken on a new urgency after a fire at the weekend killed at least seven people at Smart Export Garments in Dhaka.

The latest tragedy comes just two months after 112 workers also lost their lives in the Tazreen Fashion factory fire in Bangladesh.

Labour groups say Smart Export Garment was making apparel for European retailers including Inditex's Bershka and Lefties brands, KIK Okay (which belongs to the German discounter KIK), as well as New Look, Scott and Fox, and Solo Invest.

However, KIK has denied that it had any relationship with Smart Exports, or has received any evidence that orders were sub-contracted to the factory.

They are again asking brands to sign the Bangladesh Fire and Building Safety Agreement, and work with local and global unions to ensure that buildings are upgraded and workers can freely report safety hazards and other violations.

KIK was sourcing from Tazreen Fashion, and the same KIK label was also found at the Ali Enterprises factory in Pakistan, where nearly 300 workers burned to death last September.

Inditex and Solo Invest also both sourced from the Spectrum factory where 64 workers were killed in 2005, the labour groups say.

There have also been 18 other non-fatal apparel factory fires in Bangladesh since November.

"The recurring fires give us a clear picture that the initiative by the government and the Bangladesh Garment Manufacturers and Exporters Association to curb the death toll is too little and too late," said Kalpona Akter, executive director of the Bangladesh Center for Worker Solidarity.

"The government, BGMEA, and western retailers need to act rapidly to stop the killings and to ensure a safe workplace for our workers."

Two companies, PVH (owner of Calvin Klein and Tommy Hilfiger) and the German retailer Tchibo, have signed the Bangladesh Fire and Building Safety Agreement, which provides for such financing, bans production at any factory that refuses to make needed safety repairs, and requires public disclosure of the results of all factory inspections.

While Wal-Mart and other companies say they are taking action to protect workers, labour groups challenge the validity of those claims.

They point out that the companies have made no enforceable commitments, refuse to pay for factory renovations, and won't make the names of their factories in Bangladesh and the results of their safety audits public.