By Roch Bouka
BRAZZAVILLE (Reuters) - Police and soldiers patrolled Congo Republic's capital and cellphone networks remained cut on Tuesday as authorities took action to stem possible unrest before announcing partial results from a presidential election.
Veteran President Denis Sassou Nguesso is widely tipped to have won Sunday's vote, whose credibility the country's opposition and the United States have questioned.
Hundreds of police guarded major roads and troops were deployed near the presidential palace, the defense ministry and the main traffic circle, witnesses said, as the government extended the telecommunications blackout into a third day.
Sassou Nguesso, 72, pushed through constitutional changes at a referendum in October to remove term and age limits that would have prevented him from running again.
He has ruled the oil-producing state for 32 of the last 37 years and must win a majority against eight opposition candidates to secure a third consecutive term without a run-off.
The electoral commission said on Monday it expected to publish initial results on Tuesday. Votes from remote areas of the country are expected to take at least another day to collate.
Many residents of opposition strongholds in southern Brazzaville left the city fearing violent protests and most shops remained closed.
Voting was peaceful on Sunday but later police fired tear gas at crowds who had gathered to follow the count in the southern Bacongo neighborhood.
At least 18 people were killed by security forces in protests ahead of October's referendum.
The government had announced a shutdown of mobile phone and internet services for Sunday and Monday, which it extended into Tuesday without explanation.
The blackout was designed to prevent unofficial results circulating, Evan O'Connell, a consultant to the electoral commission, said by email.
"Rumors of landslide victories of one camp or another are already circulating online, mainly driven by the diaspora – which are the easiest way to create tensions," he said.
The opposition says the vote was marred by fraud and plans to publish its own results, an action the government says would be illegal.
The U.S. State Department said it had "received numerous reports of irregularities that have raised concerns about the credibility of the process", urging authorities in a statement to restore communications.
Congo's election is also being watched closely across Africa, where several long-ruling presidents are seeking to stay on beyond constitutionally mandated term limits.
In neighboring Democratic Republic of Congo, opponents of President Joseph Kabila accuse him of trying to delay a presidential election scheduled for November. Kabila has declined to comment publicly on his political future.
(Additional reporting by Lesley Wroughton in Washington and Aaron Ross in Kinshasa; Writing by Aaron Ross; Editing by Matthew Mpoke Bigg and John Stonestreet)