By Alsayyed Saber

CAIRO

At least 18 Egyptian security personnel were killed in Egypt’s Sinai Peninsula on Monday when their vehicles struck a series of roadside bombs, according to local security sources.

Three police vehicles had been driving along the road linking the Sinai city of Bir al-Abd to the northern city of Al-Arish when they struck a series of improvised explosive devices, local media quoted unnamed security sources as saying. 

According to the same sources, casualties included a number of high-ranking officers.

No group has claimed responsibility for Monday’s attack, while the Egyptian authorities have yet to comment on the incident. 

The U.S. strongly condemned the attack, pledging to "stand with Egypt as it confronts the threat from terrorism. 

"We express our profound condolences to the families and friends of the victims and our wishes for a speedy recovery for those hurt in the attack," State Department spokeswoman Heather Nauert said in a statement. 

Turkey also condemned, calling it a "terrorist attack" late Monday.

"We convey our condolences to the bereaved families and the people of Egypt and wish a speedy recovery to the wounded," the Turkish Foreign Ministry said in a statement.

The Sinai Peninsula has remained the epicenter of a deadly militant insurgency since 2013, when Mohamed Morsi, Egypt’s first freely-elected president, was ousted and imprisoned in a bloody military coup. 

Since then, hundreds of Egyptian security personnel have been killed in attacks across Sinai -- especially in the peninsula’s volatile northeastern quadrant, which shares borders with both Israel and the Hamas-run Gaza Strip. 

The Egyptian authorities claim they are battling the Welayat Sina, or “Province of Sinai” group, which is said to have links to the Daesh terrorist organization.

*Michael Hernandez contributed to this report from Washington and Fatih Hafiz Mehmet contributed from Ankara.