Thirty people were injured when clashes broke out between Christians and Muslims in a rural area in northern Egypt, media reports said.

Fighting erupted late Friday in the north-western governorate of Mersa Matrouh over a fence Muslims said had been built to take over a piece of land to build a church, the BBC reported.

The al-Bashayer news website said 18 of the injured were Coptic Christians. Police cordoned the area after arresting suspects, and angry people from both sides were throwing stones at cars and nearby shops, it said.

Clashes between Egypt's Christian and Muslim populations are rare, but tensions do periodically erupt over disputes about women's issues or the construction of houses of worship.

The Mersa Matrouh unrest was the first time such clashes had erupted in northern Egypt. Fighting previously had taken place in southern Egypt, where a large number of Christians live.

In the worst sectarian attack in years, eight Christians and one Muslim police officer were shot to death Jan 6 when gunmen opened fire on Christians leaving a Coptic Christmas Eve Mass in the town of Nagaa Hamadi, 650 kilometres south of Cairo.

According to government figures, Christians account for roughly 10 percent of Egypt's population, but many Egyptian Christians said they believe the real figure is higher.