The mining giant has suspended coal exports from Tete province due to security concerns after threats by the opposition Renamo party to disrupt the Sena railway line, a provincial official said on Wednesday.
"As for Rio Tinto's goods trains, the company decided to suspend them," Tete provincial governor Rachid Gogo told Radio Mozambique.
A company spokesperson in Johannesburg was not immediately available for comment. Officials at Brazilian mining giant Vale, the other commercial user of the Sena line, were also unavailable.
Renamo, a former guerrilla movement that waged a 1975-1992 civil war, has threatened to renew hostilities against the ruling Frelimo party this year in an attempt to wring political concessions out of the government.
Last week it issued a public threat to disrupt traffic on arterial roads and the Sena line, the only railway leading from the massive coal fields around Tete to the Indian Ocean port of Beira.
Since the announcement, gunmen have ambushed several trucks and buses on roads in the central belt of the southern African nation, killing at least two people and forcing vehicles to travel in convoys with military escorts.
So far there have been no reported attacks on the Sena line, a frequent target during the post-independence fighting between Frelimo and Renamo, which was founded with the help of white-ruled Rhodesia and apartheid South Africa.
However, Mozambique media said passenger rail services on the line have been reduced. Foreign embassies have also advised tourists against all but essential travel in the central Sofala province, a Renamo stronghold during the war.
'Attack on a convoy'
Meanwhile, the government said on Monday that armed men struck a convoy of cars moving under military escort in restive central Mozambique early that morning as talks resumed over a list of grievances raised by Renamo.
"This [Monday] morning there was an attack on a convoy of several dozen vehicles and, as security forces responded to the attack, armed Renamo men fled into the bush," said cabinet spokesperson Alberto Nkutumula, adding there were no deaths.
Authorities at the time said they had arrested three Renamo members in the Muxungue area they suspect are linked to the pre-dawn attack.
Mozambican troops have been escorting vehicles along a 100 kilometre stretch of a vital highway threatened by armed attacks since Friday.
The latest attack came as government negotiators entered a fresh round of talks with the former rebel movement in the capital Maputo.
But hopes of a political settlement dimmed as the talks reached a deadlock once again.
"We concluded another round of dialogue without reaching agreement on fundamental questions," said Renamo's chief negotiator, Saimon Macuiane, at the start of the week.
The government said Renamo's demands were not clear.
"Sincerely we had difficulties understanding what Renamo wanted," said the government's chief negotiator, José Pacheco.
Electoral reform demands
Monday's talks stalled over Renamo's demands for electoral law reforms, without which it has threatened to boycott municipal polls in November and presidential elections scheduled for next year.
Pacheco accused his Renamo counterparts of using the threat of violence to try and gain the upper hand in the talks.
When asked how far the government would go before abandoning talks should armed attacks continue, Pacheco insisted the government would not give up.
"The government will continue to dialogue up to the very last opportunity. The government will not abandon dialogue," he told Agence France-Presse.
Neither side has pulled out of the talks, which are scheduled to go into another round next Monday.
The talks are the latest addressing Renamo's demands for more representation in the armed forces and a cut of coal and gas revenues and changes to the electoral law.
Six previous rounds of talks with the communist-rooted Frelimo government have failed.
The recent attacks have raised fears of heightening political tensions and unrest in the country where until 1992 Renamo waged a brutal 16-year civil war that claimed around one million lives. – Reuters; AFP