President Abdrabuh Mansur Hadi warned Yemenis Monday against the use of force to express political views, as he opened a national dialogue to pave the way for the drafting of a new constitution and the staging of elections.
Hadi's address to the hundreds-strong gathering at the presidential palace in Sanaa came even as activists reported that police had shot dead a protester in south Yemen who was demonstrating against the historic dialogue.
"Those who seek to impose their own approach by the force of arms are doomed to fail," Hadi said, referring to hardline southern factions who have rejected the talks.
"The question of the south is the key to resolving all problems" of Yemen, he added, however.
The dialogue, scheduled to run six months, brings together 565 representatives of Yemen's various political groups -- from secessionists in the south to Zaidi Shiite rebels in the north, in addition to civil society representatives.
They aim to draft a new constitution and prepare for general elections in February 2014, after a two-year transition led by Hadi.
The dialogue was being held as per the UN-brokered deal that eased former strongman Ali Abdullah Saleh out of office following an 11-month uprising against his 33-year rule.
In his opening speech Hadi called for a "modern state based on good governance" as he urged political forces across Yemen to "make concessions" to ensure success of the talks which according to him were "a turning point" in the country's history.
UN envoy to Yemen Jamal Benomar said there was "strong international solidarity" with Yemen at "this historic moment".
The dialogue offers "an opportunity to settle problems" in the south "where there are legitimate injustices that need to be resolved" and in the north where "Saada wars have caused deep wounds," he said referring to the northern rebellion.
The talks, originally scheduled to start in mid-November, were delayed mainly due to the refusal of some factions in the Southern Movement -- campaigning for autonomy or secession for the formerly independent south -- to join the initiative.
Most factions finally agreed to take part after months of negotiations and under UN pressure.
But the movement's hardliners led by South Yemen's former president Ali Salem al-Baid have dug in their heels, insisting instead on negotiations between two independent states in the north and south.
As the reconciliation speeches kicked-off on Monday, police shot dead a protester in Tarim, in the southeastern Hadramawt province, during a demonstration rejecting the dialogue, an activist said.
Another activist was wounded while police arrested four others in the town, Southern Movement activist Fuad Rashid told AFP.
In the main southern city of Aden, thousands of separatists descended on Al-Arood square in Khormaksar district in an anti-dialogue rally that called for secession.
"No unity, no federation. Disengagement is our demand," read one banner brandished by protesters. " Those who take part in the dialogue are abusing the sacrifices of our southern people," read another.
Hundreds of protests had camped during the night at the square.
Protesters waved flags of former independent South Yemen and portraits of Al-Baid and Hassan Baoum -- head of the Southern Movement's Supreme Council, the most powerful faction of the alliance which is also boycotting the dialogue.
Witnesses said that policemen and southern gunmen traded gunfire in Mukalla, Hadramawt's provincial capital.
Yemeni Nobel peace laureate Tawakkul Karman, an icon of the uprising against Saleh's rule, also boycotted the dialogue in protest at what she said was the marginalisation of the youth and the participation of Saleh-era officials.
"I will not participate in the dialogue, due to the obvious imbalance in the representation of the youths, women and civil society groups and the participation of people who have the blood of the revolution youth on their hands," she told AFP.
"This was not the dialogue we had called for. We will work outside the dialogue to press the transitional government and president to achieve our demands including the reunification of the army, the release of detainees, and a probe into the crackdown" on anti-Saleh protesters in 2011.