Hundreds of anti-government demonstrators have marched through the Yemeni capital, Sanaa, to call on President Ali Abdullah Saleh to step down.
Witnesses said police fired shots in the air but it remains unclear if they made any arrests.
It marks the fourth day of protests against Saleh’s 32-year rule.
He says he will quit in 2013 but has broken similar promises in the past.
The protesters also accuse him of failing to tackle unemployment and improve living standards.
Yemen is the Arab world’s most impoverished country.
Over 40 percent of its citizens live on less than one and a half euros a day.
There were a handful of pro-Saleh demonstrators, who fought the protesters near Sanaa’s Al-Tahrir Square.
Human Rights Watch says the Yemeni government has hired armed mobs in a bid to quell the unrest.