Tehran, Dec 19, 2018 (AFP) -

An Iranian member of parliament denounced the arrest of several striking workers following weeks of protests at a steel plant in southwestern Iran, the semi-official ISNA news agency reported Wednesday.

"A number of workers of the National Steel Group who had work-related complaints were arrested two days ago," Alireza Mahjoub, head of parliament's labour faction, said in a speech to lawmakers.

"This is a violation of the constitution," he added, calling on parliament to intervene to free the arrested workers.

Staff at the National Steel Industrial Group in Ahvaz in Khuzestan province have been on strike since November 9 over unpaid wages and benefits, said labor-focused news agency ILNA.

The Ahvaz protests started shortly after a strike by workers at the Haft Tapeh sugar factory in nearby Shush over wage arrears and alleged criminal activity by new private owners.

The strike at Haft Tapeh, which has around 4,000 workers, ended after the workers received their wages.

Iran has been hit by strikes over working conditions in several key sectors this year, including education, mines, transport and the steel industry, mainly outside Tehran.

In November the head of Iran's judiciary warned restive workers against creating "disorder".

"Workers should not allow their demands to become an excuse and an instrument for the enemy," Ayatollah Sadegh Larijani said, quoted by the judiciary's news agency Mizan Online.