Cairo: One policeman was killed and five others wounded in clashes with supporters of Egypt’s ousted Islamist president Mohammad Mursi in a Nile Delta city, police said on Wednesday.

Clashes erupted late Tuesday when police arrested a group of Mursi supporters, including 13 women, who were demonstrating in a nightime rally in a key square in Damietta, around 50 kilometres (30 miles) west of Port Said.

Police said an officer who was hit by birdshot during the clashes died later on Tuesday. Five other policemen, including an officer, were also wounded in the fighting.

The health ministry said a total of 22 people were wounded in the clashes.

Supporters of Mursi have regularly attempted to stage rallies demanding his reinstatement, but their demonstrations have lost momentum amid a deadly government crackdown.

Mursi was ousted by then army chief President Abdul Fattah Al Sissi after mass street protests against his sole year of divisive rule.

Meanwhile, the Egyptian military Wednesday shot dead three Palestinian gunmen who infiltrated through a smuggling tunnel in the Sinai town of Rafah on the border with Gaza, security officials said.

They said the “armed Palestinians” and the military clashed in a buffer zone established along the border.

The gunmen had infiltrated through one of the smuggling tunnels used to transport fuel and food supplies to the Gaza Strip.

Cairo accuses militants of the Palestinian movement Hamas, which controls Gaza, of using the tunnels to infiltrate Egypt and aid militants who launch regular attacks on security forces in the Sinai Peninsula.

The army says it has destroyed hundreds of underground tunnels, many since the ouster of Egypt’s Islamist president Mohammad Mursi in July 2013.

An Egyptian branch of Daesh has staged several deadly attacks in Sinai despite stringent security measures.

The buffer zone was established after 30 soldiers were killed in a deadly attack in North Sinai last October.

Egyptian authorities have also passed a law laying down life jail sentences for the building or use of illegal tunnels.