Yemenite authorities arrested dozens of people over the weekend in an attempt to curb the violent demonstrations which broke out last week.
Amnesty International expressed concern that the detainees reportedly include children and that they stand the risk of being tortured.
Yemenites took to the streets last week to protest a government decision to cut subsidies for petroleum products, a measure that nearly doubled the price of petrol.
Opponents of the decision said the poor will carry the main burden of the cut, which will also widen the gap between rich and poor in the country.
Security forces detained 15 people in Dali, where witnesses said protesters damaged shops and electricity poles and dozens others were detained in Loder.
Yemen, located south of Saudi Arabia, produces oil but it is one of the poorest countries in the world, with nearly half the population living beneath the poverty line.
The country also suffers from a high rate of unemployment and low rate of literacy, especially among women.
According to news reports, clashes between demonstrators and security forces left at least 39 dead, although the Yemenite government put the death toll at 22. The dead include security personnel.
Yemenite President ‘Ali ‘Abdallah ‘Salih said on Saturday that those responsible will be pursued and tried.
Meanwhile, armed tribesmen seized at least 60 gas tankers near the capital ‘Sana to prevent the vehicles from reaching their destination.