About 300 people in a restive northern region of Algeria have joined a public lunch during Ramadan to protest against what they say is persecution of people who refuse to observe the religious fast.

The lunch on Saturday was highly unusual for North Africa, where people can be arrested for not fasting during the Muslim holy month.

It was held as a demonstration against the decision of security forces to question three young people who were eating outside last week in the Kabylie region during the 18-hour daily fasting period.

"We called this gathering to denounce the inquisition and persecution of citizens who, because of their beliefs, refuse to observe the fast," said Bouaziz Ait Chebib, head of the local Kabylie Autonomy Movement.

The Berbers of the Kabylie are known for a more secular outlook in general than Algeria's majority Arabs, and have had a historically tense relationship with Algeria's government.

In previous years, Kabylie residents who refused to fast during the month of Ramadan faced charges of "acting against Islam".

The lunch in Tizi-Ouzou, about 100 kilometres from Algiers, was not contested by locals who were fasting, nor authorities.