Islamic militants have unleashed a suicide car bomb and heavy gunfire on an Egyptian military checkpoint in north-eastern Sinai peninsula, leaving 23 troops dead, authorities said.
Officials said the blitz began when a suicide car bomber rammed his vehicle into a checkpoint at a military compound in the southern Rafah village of El-Barth, followed by heavy gunfire from dozens of masked militants on foot.
The dead included a high ranking special forces officer, Colonel Ahmed el-Mansi, and at least 33 others were wounded in the attack.
Army spokesman Tamer el-Rifai said the army foiled attacks targeting a number of other checkpoints in southern Rafah and that 40 militants were killed.
No group has claimed the attack but Egypt has been battling a stepped-up insurgency in northern Sinai, mainly by militants from an Islamic State affiliate.
Security officials said the militants arrived at the site - in a remote desert area - in 24 SUVs, and opened fire on the soldiers with machine guns for nearly half an hour. The force at the compound is estimated at 60 troops.
After the attack, the militants looted the checkpoint, taking weapons and ammunition. It was unclear if they took over armoured vehicles as well.
Witnesses said they saw Apache helicopters carrying out air strikes across Rafah after the attack.
The next army compound is an hour's drive away, which left the soldiers with no support except for local tribesmen from Tarabeen who have their own small checkpoints nearby.
The area of the attack is an IS stronghold and the location of fierce battles in the spring between tribesmen and militants.
Officials said some senior officers have voiced opposition to the location of the checkpoint, arguing it has no real cover.
While failing to seize territories, IS militants in Sinai have a strong presence in western and southern Rafah, the outskirts of Sheikh Zuweid, and inside the residential area of the Sinai's largest city, El-Arish.
Over the past few months, IS has focused its attacks on Egypt's Christian minority and carried out at least four deadly attacks that killed dozens, prompting army chief-turned-President Abdel-Fattah el-Sissi to declare a state of emergency in the country.
The restive north-eastern Sinai has been under a state of emergency since October 2014 after Islamic militants killed more than 30 soldiers in a single attack.
The Sinai branch of IS appears to be the most resilient outside Syria and Iraq, where the so-called caliphate is in retreat.
