Deadly protests that paralysed Mozambique's capital last week were spurred by a text message that went viral on Maputo's cell phones, signalling the power of new technology in the hands of the poor.

It is difficult to find a mobile phone user who did not get the anonymous SMS message presaging the three days of violence which left 13 dead and about 400 wounded as police clashed with people protesting sharp increases in the cost of living.

"Mozambican, prepare yourself to enjoy the great day of the strike," it said.

"Let's protest the increase in energy, water, mini-bus taxi and bread prices. Send to other Mozambicans."

The message, and the ensuing unrest, shows the new organisational power cell phones have brought to the poor in a country where 65 percent of the population lives in poverty but exercises little political clout.

"That message went around to the whole world," said Samira, a 35-year-old who lives in Mafalala, a neighbourhood of tin shacks on the edge of Maputo that saw some of the deadliest violence.

"Even me, when I saw the message I forwarded it to other people. To my friends, my sister. 'I'm asking you, please read this message'."

"There have been protests before, but they were never organised by SMS," said Hares Serafim Mulango, an 18-year-old high school student from Mafalala.

"SMS is easier, because with SMS they tell you about situations far away from you."

Organising formal protests is difficult in Mozambique, where getting a permit to march is a time-intensive bureaucratic procedure.

The explosion of cell phones has given the poor access to a political platform unavailable to them before.

"This technology is a new way of giving a voice, of giving power, of giving a means of expression that poor people themselves don't have," Joao Pereira, director of the Mozambican Civil Society Support Mechanism, told AFP.

"That group is never represented. That group is made up of the people who vote the least," he said.

Only about a quarter of Mozambique's 20 million people have cell phones, but that's twice as many people as have access to electricity, and the number has been growing by about 50 percent a year since 2004, according to the UN's International Telecommunication Union.

The cell phone messages added to the embarrassment the protests posed for President Armando Guebuza and ruling party Frelimo, in power since Mozambique gained independence from Portugal in 1975.

Guebuza swept to victory in a 75-percent landslide in elections last year, but his government has been unable to stop the recent slide of Mozambique's currency, the metical, which has plunged 43 percent against the South African rand.

The drop in value has made residents of the import-dependent country struggle to buy basic necessities.

After an emergency cabinet meeting Thursday ended with an appeal for calm and a statement that price increases were "irreversible", more text messages circulated criticising the government's response.

"Mozambicans, the government appears to have met just for a coffee and whiskey and not to resolve the problems of the people," said one message.

Pereira said cell phone technology is giving the poor a voice in politics in a country with a weak opposition, and where media are dominated by the state-owned newspaper and television station.

"It's an instrument of empowerment. It's a way of increasing the participation of the most marginalised parts of this society in the democratic system," he said.