Suspected ISIS gunmen attacked Friday an army checkpoint in Egypt’s Sinai Peninsula, killing 12 soldiers in North Sinai province and injuring eight more, according to security and medical officials.

They said the attack took place about 80 kilometers (50 miles) east of the Suez Canal near the town of Bir el-Abd, where the wounded were taken for treatment before they were ferried to the city of el-Arish to the east. It is the first major attack in the central Sinai area, which had so far escaped a campaign of Islamist attacks.

The officials, who spoke on condition of anonymity because they were not authorized to speak to the media, said a gun battle erupted after the militants opened fire on the checkpoint with light arms and heavy machine guns.

There was no immediate claim of responsibility for the attack, which bore the hallmarks of the local affiliate of the extremist ISIS group. Called the “Emirate of Sinai,” the group is leading the insurgency in the strategic region bordering Israel and the Hamas-ruled Gaza Strip.

An Islamist insurgency in the rugged and thinly populated Sinai Peninsula gained pace after the Egyptian military overthrew President Mohamed Mursi of the Muslim Brotherhood, Egypt’s oldest Islamist movement, in mid-2013 following mass protests against his rule.

The militant group staging the insurgency pledged allegiance to ISIS in 2014 and changed its name from Ansar Bayt al-Maqdis to Sinai Province. It is blamed for the killing of hundreds of soldiers and policemen, and has started to target Western targets within Egypt.

President Abdel Fattah al-Sisi, the former military chief who led the overthrow of Mursi, describes Islamist militancy as an existential threat to Egypt, an ally of the United States. ISIS controls large swathes of land in Iraq and Syria and has a strong presence in Libya, which borders Egypt.