Yemen: Three killed in protests against Saleh
Three people have been killed and 18 wounded in anti-government protests in Yemen, say witnesses.
Crowds gathered in Ibb, Taiz and the capital Sanaa to demand that President Ali Abdullah Saleh leave office.
But in a defiant speech to supporters, Mr Saleh declared: "We will defend ourselves by all means."
Meanwhile, Qatar has pulled out of mediation efforts aimed at ending Yemen's political crisis, accusing the president of "indecision and delays".
The Gulf state was among six nations pushing a deal for Mr Saleh to step down after 32 years in power, in exchange for immunity from prosecution.
'Playing with fire'
In Ibb, a city south of Sanaa, three people were killed and 15 wounded when troops shot at protesters, medics and witnesses told Reuters news agency.
Three more demonstrators were wounded by gunfire in Yemen's third city, Taiz.
More than 170 people are reported to have been killed since the unrest began in January, but Yemen's 65-year-old leader has resisted calls for him to quit.
Addressing a crowd of loyalists gathered in the capital Sanaa on Friday, he called on the opposition to "stop playing with fire".
Tens of thousands of opposition protesters had gathered in Sanaa calling for Mr Saleh to "get out".
Armoured vehicles, troops and even military academy students with batons were deployed to contain a sea of protesters stretching 7km (four miles) down a main street.
An attempt by neighbouring Gulf states to resolve the crisis suffered a blow on Friday when Qatar withdrew from mediation talks, blaming the embattled Mr Saleh.
The decision to pull out was based on "indecision and delays in the signature of the proposed agreement" and "the intensity of clashes" in Yemen, the Qatari foreign ministry said.
The remaining members of the Gulf Cooperation Council - which includes Saudi Arabia, Bahrain and Kuwait - said they would try to keep the peace pact alive.
But Yemeni opposition leader Mohammed Qahtan declared the transition plan "dead" and called on protesters to "intensify the peaceful revolt" until the president stands down.