Hundreds of people demonstrated in central Tunisia on Monday against the government's failure to improve living conditions, as teachers went on strike to denounce the arrest of protesters.

In Sidi Bouzid, birthplace of last year's Tunisian revolution, protesters marched through the town to the provincial government headquarters, shouting slogans against the ruling Islamists and demanding the governor's resignation, an AFP correspondent said.

The social unrest also spread to the region of Kasserine, another key site of the 2011 uprising, where a general strike in protest at marginalisation and soaring unemployment paralysed the Laayoune locality.

And a large number of secondary school teachers refused to work on Monday in a gesture of solidarity towards those detained last week.

A dozen people were arrested last Wednesday, after several days of protests against unemployment and the high cost of living, with more activists picked up the following day.

A general strike was held on Saturday in the nearby locality of Menzel Bouzaiane to demand the release of the protesters.

Three MPs from Sidi Bouzid announced that they were starting a hunger strike at the National Constituent Assembly in Tunis to pressure the authorities to free the protesters.

They also demanded, in a statement, a halt to police and judicial proceedings against the protesters and the resignation of the Sidi Bouzid governor.

Sidi Bouzid is where the uprising began that toppled former dictator Zine El Abidine Ben Ali and touched off the Arab Spring when a street vendor immolated himself in December 2010 in protest over his own precarious livelihood.

Poor living conditions, including high youth unemployment, were a driving factor behind the revolution.

The Sidi Bouzid region, which is home to around 12,000 jobless graduates, often sees protesters taking to the streets to condemn the Islamist-led government for ignoring their grievances and failing to create jobs.

In Laayoune, in the same central-western region, residents responded to the call by trade unionists, NGOs and political parties to march in protest at poverty, unemployment and marginalisation, an AFP journalist reported.

"Laayoune has been marginalised by every regime, by the current one just like the previous ones," said Ounaies Laabidi, a trade union leader speaking at the demonstration.