- Extremist group releases unverified photos that appear to show missile striking a ship
- The Egyptian military says the ship caught fire during a firefight with suspected militants
A statement believed to be from the group, which is based in Egypt's Sinai Peninsula, claimed it used a "guided missile" to target the ship near Rafah, on the border with Gaza.
The group, which calls itself the State of Sinai, released several photos that appeared to show a projectile flying toward and then striking a military ship, causing a huge explosion.
CNN was unable to verify the authenticity of the photographs or the group's account of what happened.
Video from Reuters, filmed from a distance, showed a large plume of smoke rising from the sea.
The Egyptian army said a military vessel caught fire following a firefight between security forces and suspected militants near Rafah on Thursday.
Egyptian army spokesman Gen. Mohammad Samir said in a statement that there were no casualties in the incident, which happened when the military was patrolling the area for "terrorists."
Several militant groups have claimed responsibility for attacks that have killed hundreds of Egyptian police and soldiers over the past two years.
The State of Sinai, formerly known as Ansar Bait El-Maqdis, has claimed responsibility for the deadliest attacks.
The Egyptian army has struggled to crush the militants in the Sinai, which borders the Mediterranean Sea to the north, Israel and Gaza to the east and the Red Sea to the south.