Tehran, Sep 5 (IANS): Iranian Foreign Ministry Spokesman Nasser Kanaani has said that Iran is extremely concerned about the hunger strike over "unfavourable" jail conditions in Bahrain, the media reported.

He made the remarks at a regular press conference in the Iranian capital of Tehran while answering a question about the hunger strike at Jau prison in Bahrain, which was launched in early August by more than 800 inmates over their treatment, according to the report released on Monday.

Saying "pressure exerted by the Bahraini government on the prisoners is unjustifiable and against human dignity," Kanaani called on the Bahraini government to responsibly respond to the prisoners' demands, Xinhua news agency reported.

The hunger strike is believed to be the largest one ever in Bahrain, with the majority of the participants being political prisoners languished since 2011, according to an AFP report, citing the Britain-based Bahrain Institute for Rights and Democracy (BIRD).

In a statement published last month, the inmates complained that they were kept in cells for 23 hours per day, with neither proper medical care nor access to education or permission to pray at the mosque, said the BIRD.

The Bahraini government has imprisoned a large number of dissidents since the uprisings of 2011, when authorities crushed anti-government Shia-led protests that demanded political and economic reforms and the establishment of a constitutional-based monarchy.