Cairo: A suicide car bombing in Egypt`s Sinai Peninsula killed at least 28 soldiers Friday, in the deadliest attack on security forces since the army deposed Islamist president Mohamed Morsi last year.
Medics said 28 soldiers were killed and 31 others wounded in the attack in an agricultural area northwest of El-Arish, the main town in north Sinai.
The bombing was carried out by a suspected jihadist who rammed the checkpoint with his explosives-packed vehicle, security officials said, on condition of anonymity.
Gunmen also shot dead an officer and wounded two soldiers on Friday at another checkpoint south of El-Arish, security officials said.
Jihadists in the peninsula have killed scores of policemen and soldiers since Morsi`s overthrow to avenge a bloody police crackdown on his supporters.
President Abdel Fattah al-Sisi, the army chief who toppled Morsi and later won elections, has pledged to eradicate the militants.
After Friday`s attack, Sisi announced three days of national mourning and summoned a meeting of the national defence council -- the country`s highest security body -- to discuss the killings, his office said.
The European Union and United States both condemned the attack.
"The United States continues to support the Egyptian government`s efforts to counter the threat of terrorism in Egypt as part of our commitments to the strategic partnership between our two countries," the State Department said.
"We regret the loss of life and express our deepest condolences to the families of the victims," an EU spokesman said.
It was the latest in a string of bloody attacks against security forces in Egypt.
In August 2013, just weeks after the army ousted Morsi, 25 soldiers were killed in the Sinai when gunmen opened fire at two buses transporting troops with automatic rifles and rocket launchers.
In July this year, 22 border guards were killed in the western desert near the border with Libya.
Militants killed 17 policemen in two bombings in the Sinai later the same month and released footage of the attacks.
Those bombings were claimed by Ansar Beit al-Maqdis, the most active militant group in Egypt.
From the desert and mountainous Sinai, which borders the Gaza Strip and Israel, the attacks have also extended to the capital and the Nile Delta to the north.
Ansar Beit al-Maqdis tried to assassinate the interior minister in Cairo last year with a car bomb.
The group has expressed support for Islamic State (IS) group jihadists in Iraq and Syria, although it has not formally pledged its allegiance.
The military has said it killed at least 22 militants in October, including an Ansar Beit al-Maqdis commander.
The group itself has acknowledged the arrest or deaths of militants, but the army has been unable so far to crush them despite a massive operation in which it has deployed attack helicopters and tanks.The latest bombing came after an Egyptian military court sentenced to death seven members of Ansar Beit al-Maqdis on Tuesday for carrying out deadly attacks on the army.
Since Morsi`s ouster, more than 1,400 of his supporters have been killed in a crackdown by the authorities.
Over 15,000 others have been jailed including Morsi and the top leadership of his Muslim Brotherhood, and more than 200 sentenced to death in speedy trials.
The authorities have also dissolved the Brotherhood`s political arm, the Freedom and Justice Party, since Sisi became Egypt`s second democratically elected president following a landslide victory in a May vote.
The secular April 6 movement, which led the 2011 revolution that ousted president Hosni Mubarak, has also been banned, prompting activists to charge that Egypt was heading to a worse autocracy than under the longtime ruler.