BANGUI, Central African Republic -- The mayor of a Central African Republic (CAR) town says at least 100 people are dead after heavy fighting broke out in the wake of a peace agreement signed this week in Rome.

Bria Mayor Maurice Balekouzou also said Wednesday that several dozen wounded have been brought to the hospital run by aid group Doctors Without Borders.

However, the local Catholic mission says the death toll could be higher because it has been too dangerous for Red Cross teams to recover bodies from the streets.

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Wracked by civil war, CAR is a country teetering on the edge of becoming a failed state. As CBS News' Allen Pizzey reported a year and a half ago, half a million of the country's people have become refugees in neighboring nations, and a similar number are huddled in squalid camps inside CAR, dependent on food aid and the protection of U.N. peacekeepers and 900 French troops.

CAR has faced fighting since 2013, when predominantly Muslim Seleka rebels seized power in Bangui. Anti-Balaka militias, mostly Christians, fought back, resulting in thousands of people killed.

Witnesses say the fighting that left at least 100 dead on Wednesdday took place between the anti-Balaka militia and rebels from the group known as FPRC who were once part of the Seleka movement.

The peace deal signed Monday between nearly all the country's armed groups had called for an immediate cease-fire.

In December 2015, Pope Francis shunned security concerns to ride in an open-top vehicle across what was then the front line in the vicious civil war to visit a mosque in a part of the capital known as PK5; the last Muslim enclave in Bangui.

"Christians and Muslims are brothers and sisters," he said after meeting Muslim leaders at the Koudoukou mosque. "Together we must say no to hatred, to revenge and to violence, particularly that violence which is perpetrated in the name of a religion or of God himself."

Gunfire also was reported Tuesday in the towns of Bangassou and Alindao, according to the global non-profit group Doctors Without Borders, which said the security situation "remained extremely volatile."

The peace deal was brokered by the Sant'Egidio Catholic Community, though there was widespread skepticism in CAR, given similar failed efforts in the past.

Sant'Egidio organization president Marco Impagliazzo (R) and Republic of Central Africa foreign minister Charles Armel Doubane (2-R) address a political delegation from Central African Republic on June 19, 2017 inside the Sant'Egidio community church in Rome. Getty

Ten armed groups and the country's Defense Ministry signed a peace deal in 2015. Another accord, shepherded by the African Union, was signed in 2014. Neither lasted.

"The priority now is a cease-fire," Vlad Monteiro, a spokesman for the U.N. peacekeeping mission said Tuesday. "The armed groups should cease the hostilities and put an end to people's suffering."