At least one person has been killed and nine wounded in clashes between Yemeni police and demonstrators protesting against rising prices in the capital, Sanaa.
Yemen has banned protests organised without permission after opposition parties staged several protests in recent weeks to demand the government acts to curb rising prices.
Hussein Basaleh, the head of a human rights group in Sanaa, said on Sunday: "The demonstrator was killed during disturbances that lasted several hours."
He said one of those wounded in Saturday's clashes was in a critical condition and witnesses said police made several arrests.
Government officials say the rise is due to a sharp increase in the prices of commodities such as wheat in global markets.
The government has ordered state bodies to import goods and provide them at lower prices.
Retiree anger
About 100 people were arrested on Friday in the southern port city of Aden while preparing to demonstrate for better benefits for retired personnel but most were later freed, witnesses and officials said.
The Council for the Coordination of Retired Groups organised the protest to demand increased support for more than 60,000 retirees from the military and civil service, many of whom insist they were forced to stop work early.
On August 28 thousands of protesters gathered in Sanaa to call for the Yemeni government to resign because of falling living standards and rising food prices.
In July 2005, at least 22 people were killed and 375 wounded when police clashed with demonstrators during two days of protests in Sanaa and several provincial towns against a sharp rise in fuel prices.
Four out of 10 Yemenis live on less than $2 a day, according to Britain's department for international development, which says Yemen's oil, its main earnings source, is expected to dry up by 2015.