CAIRO - Suspected Islamic militants on Wednesday launched a wave of coordinated attacks on Egyptian army checkpoints in the restive north of Sinai Peninsula, killing at least 50 soldiers, security and military officials said.

Of the death toll, 11 were killed in suicide car bombing which targeted one of the checkpoints, the sources told Xinhua.

The attacks took place south of the town of Sheikh Zuweid, the officials said, adding that the militants also took several soldiers captive and seized weapons and several armored vehicles.

The officials said the attackers used mortars, rocket propelled grenades as well as assault rifle. At least 40 other soldiers were wounded in the attacks.

Meanwhile, Egypt's military spokesman, Mohammed Samir, said in a statement that some 70 militants attacked five checkpoints in northern Sinai and that Egyptian troops killed 22 off them and destroyed three all-terrain vehicles fitted with antiaircraft guns.

A Sinai-based Ansar Baiet al-Maqdis which pledged allegiance to the Islamic State has claimed responsibility for the attacks.

"In a blessed raid enabled by God, the lions of the caliphate have simultaneously attacked more than 15 checkpoints belonging to the apostate army," the group said in a statement posted on social media websites.

Northern Sinai witnessed escalated anti-security attacks by Islamist militants after the ouster of the Islamist President Mohamed Morsi in 2013 by the army, in response to mass protests against his rule.

The Islamists have pledged revenge attacks over the past two years for the country's security crackdown and jailing of Morsi's supporters.

Thousands of Islamists were detained, and hundreds of which were handed down death and life sentences in swift trials after the army toppling of Morsi.

Morsi himself was sentenced to death over jailbreak and life sentence over spying for foreign bodies against the national security of the country.

Wednesday's attacks came two days after the assassination of the country's top prosecutor, Hisham Barakat, and one day after President Abdel Fattah al-Sisi vowed retaliation and pledged tougher laws in dealing with terrorists.

The IS branch based in Sinai has posted an audio massage on Monday, the same day of Barakat's assassination, showing the murder of three judiciary men in May in Sinai and pledging more attacks against security and judiciary staff.