Yemen unrest: 'Troops attack' opposition camp in Sanaa

Government troops in Yemen have opened fire on protesters in Sanaa, killing at least one person, reports say.

Witnesses and medics say the demonstrators came under gun and mortar attack in the capital's Change Square - the focus of the protests.

They say some tents were on fire and there were also sniper attacks.

The violence comes after President Ali Abdullah Saleh earlier returned from Saudi Arabia three months after surviving an assassination attempt.

"We have six severely injured and one killed in a terrible way by the mortar fire," doctor Mohammed al-Qubati was quoted as saying by Reuters.

There were also reports that late on Friday government troops tried to storm the square, which was being guarded by armed men opposed to President Saleh.

Activists have been camped out in Change Square since January, demanding an end to Mr Saleh's decades-long rule.

Earlier on Friday, at least 13 people reportedly died in fighting in the capital. Clashes in the capital have recently intensified as elite Republican Guards, led by President Saleh's son Ahmed, fight running battles with army units that have defected to the opposition and tribal fighters who support the protesters.
Civil war risk

After his surprise return to Sanaa, President Saleh called for a ceasefire to stop violence which has already claimed about 100 lives already this week, mainly of unarmed anti-government protesters.

He flew back after having treatment in Saudi Arabia for injuries sustained in a rocket attack on the grounds of his presidential palace.

Mr Saleh was greeted by thousands of enthusiastic supporters, who staged a rally in Sanaa.

But correspondents say his return raises the risk of all-out civil war.

The US, whose officials were reported to have been taken by surprise by President Saleh's return, urged him to begin a transfer of power and arrange presidential elections.

"The Yemeni people have suffered enough and deserve a path towards a better future," White House spokesman Jay Carney said.