By Serajul Quadir and Ruma Paul

DHAKA (Reuters) - A police case has been filed against the owner of Tampaco Foils and seven other top managers of the food and cigarette packaging plant near Dhaka who have gone into hiding, as the death toll from a fire at the factory over the weekend rose to 33 late on Monday.

The blaze erupted early on Saturday morning and became Bangladesh's worst industrial accident since the collapse of the Rana Plaza building in 2013 that killed 1,135 garment workers. It has raised renewed questions about industrial safety in the country, which is one of the world's top garment exporters.

"A murder case has been filed against eight people including the owner of the factory. All of them have gone into hiding. We are doing our best to arrest them," said Aminul Islam, who is an inspector at the local police station. He said the case had been filed by the family of one of the victims.

The deputy inspector general of factory inspection said that authorities also plan to file cases against the company and its owner for violating building and safety codes.

The factory is owned by Syed Mokbul Hossain, a former member of parliament. Hossain told Reuters on Saturday that Tampaco was "fully compliant." But he could not be reached by telephone to answer further questions on Monday.

Jahirul Islam, a director with the fire service department, said on Monday the Bangladeshi army had joined search efforts at the site of the fire.

"We need to move a huge amount of debris otherwise searching is not possible," he said.

Many fear the death toll could rise further as the search continues and a few people remain missing after the blaze caused a partial collapse of the factory building.

The cause of the fire in the Tongi industrial zone about 20 km (12 miles) north of the capital, Dhaka, was not immediately known, but officials said a gas line leak and a boiler explosion probably triggered it.

"It may take two months to remove the debris of the factory. The debris is more than that of Rana Plaza," said Brigadier General Mahmud Hasan, commander of the army unit working on the search effort.

The fire is the latest in a series of industrial accidents in the South Asian country. It comes just weeks after over 100 people fell ill after inhaling gas that leaked from a fertilizer plant in Chittagong in southern Bangladesh.

Tampaco Foils makes packaging for food and cigarettes for a number of local companies and global brands like British American Tobacco and Nestle.

A spokeswoman for Nestle said the plant produced packaging for products like its Maggi Noodles in Bangladesh. She said the factory had passed a fire safety and prevention audit run by a third-party inspection firm in late 2012. Nestle had been in the process of organizing a new audit of the company just before the accident occurred.

"We are currently unaware of the precise cause of the fire, but have been informed that the Bangladesh government has set up a formal investigation. We will need to await the conclusion of this before we can comment any further on the details," said a spokesman for British American Tobacco, adding the focus was now on offering humanitarian support to Tampaco.

(Additional reporting by Martinne Geller in London; Writing by Euan Rocha; Editing by Michael Perry and Hugh Lawson)