At least four people demonstrating against plans to lift presidential term limits in Congo Republic were killed when police opened fire when the crowd refused to disperse, protesters said.

Thousands of opposition supporters took to the streets against Sunday's planned referendum on removing constitutional term limits for President Denis Sassou Nguesso, who has ruled the oil producer for all but five years since 1979.

Marchers, waving banners reading "Sassou get out" and "No to the referendum", scattered after the police fired warning shots and teargas but remained on the streets, burning tyres and erecting barricades.

Police stations were attacked in the south of the city, an opposition stronghold, in the latest bout of violence to erupt as a result of an African leader trying to extend his rule.

When demonstrators refused to disperse, protesters said security forces turned their guns directly on the crowd. A Reuters witness saw four bodies, marked with bullet holes, brought to the morgue of the southern Makelekele district.

"I was there when they opened fire," said one protester who brought his friend's body to the morgue, declining to give his name. "I was lucky it wasn't me who was killed. All this because of a president who doesn't want to go."

Paulin Makaya, leader of the opposition United for Congo party, said: "President Sassou Nguesso is organizing a coup d'etat, a constitutional coup d'etat."

"We are not going to back down ...I will return to the streets tomorrow," he said, appealing to Western nations to take action.

OIL HUB

Protests were also reported in the coastal oil hub of Pointe-Noire, where tensions have run high since four people were shot by a police officer at a rally on Saturday.

Residents said the violence in Brazzaville was amongst the worst since Sassou Nguesso retook power in 1997 at the end of a brief civil war. Calm returned as night fell with only sporadic shots reported in the south of the city.

The protests came just over a year after efforts by Burkina Faso's former veteran leader Blaise Compoare led to his toppling in a popular uprising. Burundi's President Pierre Nkurunziza overcame violent protests to extend his rule this year.

In a speech in neighboring Democratic Republic of Congo, U.S. Under Secretary of State for Civilian Security, Democracy, and Human Rights Sarah Sewall accused Congo Republic's government of arbitrarily detaining opposition supporters and using live fire against protesters at the weekend.

"It's too early at this point ... to say what specific (sanctions) might be considered," Sewall told Reuters. "It's just unfortunate that there's so much need to consider them."

Although Sassou Nguesso is barred from seeking a third term due to age and term limits, the 71-year-old is expected to be a candidate at elections scheduled for next year. His proposed constitutional reform would remove these restrictions.

Thousands of people took to the streets last weekend in favor of the constitutional change.

Mobile Internet and text messages were down in Brazzaville, residents said, and Radio France International (RFI) said its signal had been blocked. Shops, schools and government buildings were closed, and many streets were deserted.

Government spokesman Thierry Moungalla said Internet and phone services were crashed by high demand from users.

"The radical opposition promised to march on the presidential palace today so it's logical security forces took steps to preserve the peace of our citizens, freedom of movement and the stability of the state," he told RFI.

 

(Additional reporting by Aaron Ross in Kinshasa; Writing by Makini Brice; Editing by Daniel Flynn/Ruth Pitchford)