DOUALA, Cameroon (AP) _ Charred furniture and windows shattered by firebombs warn shopkeepers of the perils of breaking the pro-democracy strike that has paralyzed most of this central African nation.

Operation Ghost Towns - as opposition parties have dubbed their revolt against President Paul Biya - entered its seventh week Saturday with a toll estimated by diplomats and witnesses at about 100 people killed. Hundreds are jailed.

''This is war, not a strike,'' said a waiter who feared attacks if he was identified by name.

About 60 people have been shot by police and soldiers, according to the diplomats and witnesses. Two policemen have been stoned to death by protesters. And about 40 people died in fighting between ethnic Fulbe opposition supporters and the ethnic Beyas who back the government - inviting fears the rebellion could erupt into a tribal conflict.

Opposition leaders said the strike would not end until Biya ends his 9- year-old rule and calls a national conference to name an interim government to oversee elections. They accuse the president of corruption, mismanagement and tribalism.

Biya has steadfastly refused to such a conference, which have stripped leaders of power in Benin, Congo and Niger.

Biya accuses the opposition was trying ''to stage a civilian coup d'etat.'' The beleaguered leader - among a handful of civilian presidents in a region dominated by military rulers - won a five-year term in 1988 as the sole presidential candidate. Biya was handed power in 1982 by President Ahmadou Ahidjo.

In May, other strikes and protests forced Biya to legalize political opposition, ending 19 years of single-party rule. Last month, under pressure from the strike, Biya offered to call early elections. But opponents claimed he would rig the balloting.

Meanwhile, Biya's hardball tactics to try to break the strike are not working. Only Yaounde, the administrative capital, and the area around it has been spared.

In Douala, the nation's main port and largest city, Provincial Gov. Albert Ekono Na persuaded Greek businessman Nicholas Stamatiades to open his furniture and appliance store last week under military guard.

On Sunday, hundreds of people attacked with firebombs, gutting the shop.

Opposition leaders deny it was pro-democracy protesters, though protesters are blamed by diplomats and journalists. The opposition blamed the military trying to extort money.

''That was a well-planned attack, carried out by soldiers,'' said Yondo Black, of the Movement for New Democracy.

Stamatiades and his director left the country after the attack, the store receptionist said.

Prince Dicka Akwa nya Bohambella, leader of one of the biggest of the 35 opposition parties, said 518 people were arrested when soldiers attacked a rally following the fire. Diplomats said about 300 people were detained.

Police Commissioner Ebenezer Peh Peh refused to say how many people were arrested. Said the governor: ''They committed terrorism. They were arrested.''

Opposition leaders and diplmats said it was impossible to say how many others have been detained or killed since May in the strikes and protests.

Estimates ranged from about 100 deaths to more than 200.

People in Doula said the strike is hurting them, but they would not stop.

''We are suffering,'' said Joseph Ngningaye, a photographer in the city of 1.5 million people. He said he had to walk three miles to his shop because taxis are not running, and his earnings have dropped from about $100 a week to $12 to $15.

The strikers allow shops and businesses to open Saturdays and Sundays. Supermarkets are so crammed people line up on the sidewalk. Music starts blaring from restaurants that are barred and shuttered during the week, and Douala's 10,000 taxis take to the street.

Buses and taxis have been burned and stoned for trying to defy the strike, though private cars generally are allowed to run. The opposition said its strategy of allowing two days for people to work and stock up food would allow the strike to continue while slowly bleeding the economy.

It is difficult to estimate the economic consequences of the strike.

National Assemblyman Gregoire Owona estimated the strike was costing the economy $1.3 million a day.

''If Biya doesn't move, he will be pushed out of power... by a coup, or by crowds going into the street. I don't know how,'' he said.

This week, the opposition put out a new order for people to stop paying utility bills.

''It doesn't matter,'' said Ngningaye. ''Most of us don't have any money left.''