The Egyptian affiliate of the Islamic State says it has carried out a missile strike on an Egyptian navy vessel off North Sinai, the SITE intelligence group reports Thursday.
Pictures posted online appear to show the frigate being hit by a rocket. The authenticity of the images could not be confirmed.
Egyptian officials had said the the navy vessel caught fire following a clash with militants and that there were no fatalities among it's crew.
"The [coastguard] launch crew suspected the movements of some terrorist elements on the coast, so it chased [them] and exchanged gunfire, which led to the launch catching fire without loss of life," said the statement posted to Facebook.
Egyptian military sources said the suspected militants had fled after firing on the vessel.
A Reuters witness in Gaza saw a plume of dark grey smoke rising from a boat off the coast. Other witnesses in the Palestinian enclave said they heard explosions and gunfire.
An Israeli military spokeswoman said Israel was not involved in the incident and had not been asked to assist.
In November, four assailants were killed and 32 people detained when gunmen in a fishing boat opened fired on an Egyptian naval launch north of Damietta port, near the Suez Canal and west of Thursday's incident.
Earlier this month, IS claimed responsibility for a massive terrorist attack on Egyptian army checkpoints on the Sinai Peninsula, killing at least 64 soldiers.
One top official said the attack was "unprecedented in the number of terrorists involved and the types of weapons they are using," including rocket-propelled grenades and car bombs.
Reuters information was used in this report.