Five Iran soccer fans have been trampled to death after a 2006 World Cup qualifier against Japan in Tehran, the state news agency state IRNA news agency reports.

They died as the 100,000-strong crowd was leaving Tehran's Azadi stadium on Friday. More than 40 others were reported injured, some critically.

The interior ministry said it would launch an investigation. Three of those who died have yet to be identified. Iran won the Asian zone Group B game 2-1.

Also read: Japan, South Korea stunned in Asian qualifiers