A call by the defeated opposition candidates in the Comoros for a mass protest against President Azali Assoumani's re-election went unheeded Friday, confronted by a heavy security presence.

The opposition challengers urged people across the Indian Ocean island chain to block roads after Friday prayers to denounce Assoumani's "electoral masquerade".

But turnout was half the usual number at Friday prayers at the largest mosque in the capital Moroni, worshippers said, and there was no sign of political agitation afterwards.

Police and soldiers were deployed around the medina market area on key junctions, some of them hooded or wearing surgical masks to hide their identities.

Bilali Soidiki, a supporter of opposition challenger Bourhane Hamidou, blamed the government's clampdown on communications -- internet services have been disrupted since Wednesday.

"The government is preventing any communication," he told AFP.

"With the internet shutdown it was difficult to mobilise, especially when the five candidates' call to demonstrate was announced at night."

Moroni had been paralysed by two days of running street-battles between stone-throwing youths and armed soldiers.

At least one person was fatally wounded, according to medics.

But, while tensions remain high, some in the city took advantage of the break in hostilities on the day of prayer to try to get their businesses up and running.

"Because of the riots I've had two days without work," sighed stallholder Said, grilling chicken wings near the mosque and complaining about the quality of his charcoal.

- US call to 'clarify' -


While the opposition blamed the government crackdown for the lack of mobilisation, one of the youths whose protests have rocked the capital had a different explanation.

Kassim Omar Abdou, a student in his 20s, joined a protest group from a slum in the south of the city and has a bandage on his leg where he was hit by a teargas grenade.

On Friday, the slum was strangely calm.

"They received money this morning in exchange for a promise to stop everything," Omar Abdou said of his comrades.

Other witnesses confirmed this turn of events to AFP.

Assoumani's victory is expected to be confirmed by the supreme court at the weekend after the electoral commission declared he had won more than 60 percent in Sunday's first-round vote.

But the opposition says the unexpectedly low 16-percent turnout figure in the presidential vote falls far short of the figure for parallel governor polls.

According to the official tally, 189,497 Comorans voted to choose governors for each of the three islands in the archipelago, but only 55,258 cast a vote for president.

On Friday, the US embassy in Moroni expressed concern about the results and urged the electoral commission to "clarify" them before they are validated by the supreme court.

The embassy said the results announced by the National Independent Electoral Commission (CENI) raise "serious concerns that must be addressed to maintain the peace and the well-being of the nation".

"We call on the CENI, and Comoran authorities, to ensure full transparency and clarify the results it announced," the embassy said.

France, which was the islands' colonial power until independence in 1975, also expressed concern, urging "all Comoran actors to favour restraint and dialogue".

The UN and the EU have previously called for calm.

And on the higher turnout for gubernatorial elections than for the presidential vote, the US embassy said this "was not apparent to domestic and international elections observers".

Assoumani, a 65-year-old former military ruler turned civilian president, has dismissed the concerns.

A nightly curfew was declared to curtail the unrest.

Some 45 percent of the Comoros' population of 870,000 lives below the poverty line.