Around 250 people were injured when metal awnings collapsed on top of spectators at a sports stadium in the northern Iranian city of Sari on Sunday, the official Iranian media reported.

But hospital sources and a senior sports official denied earlier media reports that several people had been killed. State television said spectators were hurt when the awnings caved in over part of the seating area of the stadium, packed with up to 40,000 people watching a soccer game between Iran's main soccer club, Pirouzi, and a local team.

It said many people were treated for minor injuries on the spot and quoted sources at Imam Khomeini Hospital in Sari as saying 100 people were brought in for treatment, including one in critical condition and two with possible brain damage.

The sources said there were no fatalities. IRNA's English-language service had earlier quoted its correspondent on the scene as saying "several people" had been killed and hundreds injured.

The head of Iran's Physical Education Organisation, Mustafa Hashemi-Taba, later told IRNA: "Fortunately there were no fatalities in the incident". He said most of the injured were hurt in a stampede while thousands of people tried to flee the Motaqi stadium, which he said had a capacity of only 10,000.

He said the collapse was due to pressure from spectators sitting on top of the awnings. "They should not have let so many people into the stadium," he added. An injured man, interviewed by the television from a hospital bed, blamed stadium officials for allowing in such a high number of people. "All they are interested in is money," he said.

"We were sitting down and suddenly some 500 people sitting on the awnings came down on us," one witness said. The television broadcast footage showing thousands of people running in different directions, apparently trying to flee the stadium. Others were seen pointing in the direction of the affected area while some were trying to help the victims.

Rescue teams with stretchers tried to make their way through the crowds to the scene. The television said the incident took place during the halftime break and that Iran had set up a committee to investigate the accident.

IRNA later said the incident caused panic in the city and that residents had gathered outside the stadium for news of their relatives who were watching the game. Police sealed off the area to help rescue workers rush the victims to hospitals and the sirens of ambulances still wailed across the city one hour after the incident.

The television said President Mohammad Khatami had ordered an investigation into the incident and that a special commission had left Tehran for Sari to investigate the causes.