也门国内冲突已致50人死亡
Security forces in Yemen have killed more than 50 people in two days of violence against anti-government protesters, activists say, in the country's bloodiest clashes for months.
也门安全部队在近两天对抗反政府抗议者的暴力冲突中公杀死50多人，这是最近几个月以来最严重的冲突。
Snipers in Sanaa fired from rooftops at a protester camp, killing bystanders（旁观者） including a child, witnesses said.
Government forces also shelled areas held by troops loyal to the protesters.
The opposition has promised to carry on its campaign to oust President Ali Abdullah Saleh.
For months, thousands of people have been waging a campaign to depose Mr Saleh, who has ruled the country since 1978 and is currently in Saudi Arabia recovering from a bomb attack in June.
The opposition believes the government is deliberately orchestrating（精心组织） the violence to derail（出轨） any chance of agreement.
But a Yemeni minister strongly denied reports that the authorities had fired on peaceful demonstrators, telling the BBC government forces were being attacked by militants sympathetic to al-Qaeda.
The US and EU nations were among members of the UN Human Rights Council who used a meeting in Geneva on Monday to urge Yemen's government to stop using force against protesters.
Meanwhile, as the violence intensified, envoys from the UN and the Gulf Co-operation Council arrived in Yemen, in a new attempt to negotiate a handover of power from Mr Saleh.
Air attacks
The last two days have seen the worst violence in the country for several months: on Sunday, 26 people were killed and many more injured as they marched towards the presidential palace in Sanaa, the capital.
But protest leaders issued a rallying cry urging more demonstrations on Monday, in which at least 27 people died as security forces once again opened fire on civilians.
Reports say snipers began firing at a protest camp shortly after leaders of the demonstrations had begun to use loud-hailers to urge more action.
The snipers killed several people - among them a child who was unconnected with the protests - activists said.
The boy's father told the Reuters news agency: "I stepped out to get some food and left my two boys in the car and I heard the older one scream. The little one was shot straight through the head."
In another part of the city, a firefight broke out between government troops and soldiers loyal to the protesters.