The latest conflict on Saturday, occurred in the southern city of al-Dhalea, Aljazeera's correspondent in Yemen reported.
This follows several days of protest since last Wednesday, which has left up to 39 people dead, according to news agencies. The government puts the toll at 22.
There was no word on casualties in Saturday's clashes.
Security forces backed by tanks clamped down on protesters across Yemen on Friday, deploying around mosques, after dozens were killed in clashes this week.
Still, some protests continued. Tribesmen in the northeast blocked a main road linking the oil-rich area of Saffer to Sanaa for a second day, preventing petrol tankers from travelling to the capital.
Oil Ministry officials confirmed that supplies had failed to get to Sanaa because of the tribesmen's blockade.
Anticipating large protests after Friday congregational prayers, security forces, army units and tanks deployed on main streets and around the major mosques in the capital.
Small groups of worshippers leaving mosques were broken up by security, and others were corralled and prevented from converging.
Soldiers were deployed on the second
day of clashes after fuel price rises
On Hail Street in downtown Sanaa, security forces bolstered with armoured vehicles blocked protesters trying to move into other parts of the city.
In Dali province, 155km southwest of Sanaa, a small number of protesters stormed government offices - which were closed for Friday, a weekend day - and were later chased away by the security. There were no reports of casualties.
Deadly riots erupted on Wednesday and worsened the next day in more than half a dozen cities after the government announced the cutting in half of subsidies on oil supplies, part of new belt-tightening measures.
Fuel prices at the pump doubled to around $8 a gallon.
Yemen is an oil-producing nation, but most of its population is mired in poverty.
Yemen produces oil, but most of
its people live in abject poverty
Yemen is a close US ally in the "war on terrorism", waging a crackdown that has led to the arrests or killings of dozens of "militants".
Washington has signed an economic pact with Yemen intended to open its economy to international trade and investment.
But its decrepit economy has sparked growing resentment in the mountainous, tribal-dominated nation. Oil wealth has not made it to the public and the government has been accused of rampant corruption. Unemployment runs at 36%.
President Ali Abdullah Saleh announced last week that he would not run in presidential elections in September 2006, calling for a new generation to be allowed to govern. But many Yemenis dismissed the gesture, saying he would likely change his mind or bring his son into power.