The investigation into an industrial tragedy which killed four men in Norfolk could take weeks, police have said.

Work was being carried out at Claxtons engineering in North River Road, Great Yarmouth, at about 2pm yesterday when a steel structure collapsed, crushing four men.

The men, believed to be aged between 26 and 42 and from the Bury St Edmunds area, were trapped under tonnes of steel and pronounced dead at the scene.

Police and the Health and Safety Executive (HSE) are today continuing their investigations. While a further assessment of the site is being carried out today, Det Chief Insp Neil Luckett, of the joint Suffolk and Norfolk Major Investigations Team (MIT) said it could be several weeks before they know what caused the tragedy.

He said: 'This is a complex investigation and our enquiries - including assessments at the site - are likely to continue for several weeks.

'We will not be drawn into conjecture on the nature of the incident. The aim of our investigation is to establish the full circumstances around what happened on the site yesterday.

'This is a distressing time for the families of those who sadly lost their lives and our thoughts go out to them.'

Meanwhile, two football clubs have cancelled their matches out of respect of the men.

It is understood three of the four were from the Stanton area of Suffolk and had strong ties with both Stanton and Walsham le Willows football clubs, which postponed all of their Saturday matches.

Joy Mayhew, secretary at Stanton FC, said two of those who died were due to play against Grundisburgh today.

She said: 'It is a complete feeling of disbelief.'

Mike Powles, chairman of Walsham le Willows FC, said: 'The Walsham and Stanton games have all been called off due to the fact the men killed in the tragic accident were from the local area and had been involved in the clubs.'

Home Office post mortem examinations to determine the cause of death will take place on Monday.