Security forces have used tear gas and batons against stone-throwing protesters in the Guinean capital Conakry, say reports.

They dispersed a planned rally by opposition supporters protesting against the government's handling of preparations for parliamentary polls.

Guineans voted in presidential elections last November for the first time since independence in 1958.

But onlookers fear that the historic democratic gains could be under threat.

Parliamentary polls should have been held within six months but have now been fixed for 29 December by the authorities and the Independent National Electoral Commission (CENI).

Opposition leaders say they fear the elections will be a sham.

Leading opposition figure Cellou Dalein Diallo, who narrowly lost in last year's poll, has accused President Alpha Conde of installing a close ally as CENI head and of trying to tamper with voter rolls.

A meeting on Monday between Prime Minister Mohamed Said Fofana and opposition leaders brought no resolution and opposition leaders said they had decided to go ahead with the march despite a ban.

This was to have been the first major demonstration since last year's election and many shops and petrol stations were closed for fear that violence could break out, said reports.

Dozens of police and paramilitary force vehicles reportedly blocked access to the September 28 stadium, where the rally was to be held, and other parts of the capital.

"There were youths on the hilltops throwing rocks. The security forces fired back with tear gas, which triggered general panic," Souleymane Bah, a resident of the Conakry suburb of Bambeto, told Reuters news agency.

The crackdown on the protest was "regrettable", opposition figure Sidya Toure told AFP.

"The security forces had only to marshal the demonstration instead of preventing it," he said.

"Our pride and our satisfaction is that we have managed to paralyse the town of Conakry," he added.

The former colonial power France has called for "calm and restraint", AFP reported.