Eight Egyptian navy personnel are missing following an attack by militants on an armed forces boat in the Mediterranean, the army has said.

Five injured navy personnel have been transferred to hospital, while searches are ongoing to locate another eight, a military spokesman said late on Wednesday.

Military forces destroyed four boats used by the assailants and arrested 32 suspects, he added.

A military naval boat was performing a combat exercise in the Mediterranean, 40 nautical miles north of Damietta port, when a number of boats fired at it on Wednesday.

This is the first attack on naval forces.

No information has been released on the identity of the assailants.

The army has been combating a decade-long jihadist insurgency in Sinai, with attacks increasing over the past year and expanding into Cairo and the Nile Delta. Hundreds of soldiers and police have been killed, while the army says it has killed and arrested hundreds of jihadists. Civilians have also been caught in the violence.