Two Congolese human rights groups on Monday blamed police for a stampede that left seven people dead at the opening of a pan-African musical festival in a Brazzaville stadium.

"A police lapse led to this tragedy. Police did not take the full measure of the popularity of the shows. They should have taken security measures commensurate with the importance of the event. They under-estimated it," said Maixent Hanimbat, chairman of the Forum for Governance and Human Rights.

And Franck Loufoua Bessi, a member of the group Meeting for Peace and Human Rights, also slammed police for not taking adequate security measures during Sunday's incident.

But police spokesman Jean-Aive Alakoua defended the police's conduct.

"No one can predict crowd behavior. We should instead try to find out whether the organisers took all the appropriate measures."

Congolese Culture Minister announced Sunday that seven people died as security forces failed to control a stampede outside the Felix Eboue stadium, the venue for the 8th Pan-African Music Festival (Fespam).

"We were all surprised by this unusual turnout. The crowd outside seemed to be bigger than those inside the stadium which was jam-packed," he said.

Authorities cancelled the festival as a result.

The Fespam was created in 1996 and is held every two years under the aegis of the African Union and in partnership with the International Centre of Bantu Civilisations, the International Music Council and UNESCO.