Former presidential candidate Ahmed Shafiq saluted the Egyptian security forces who were killed in Sinai on Sunday afternoon by unknown gunmen near the Egyptian-Israeli border.

Egypt’s condemnation of the attack is not a sufficient response to that violation of the country’s national security and sovereignty, Shafiq said.

In a statement issued by his office on Tuesday, Shafiq said: “Terrorists do not care about words and are not concerned with statements. Terrorism requires clear-cut positions.”

At least 16 Egyptian security forces were killed on Sunday afternoon when unknown armed men stormed a checkpoint along the Egyptian-Israeli border near Rafah. Egyptian and Israeli officials said the assailants likely belong to extremist Islamist groups in Sinai.

Egyptian President Mohamed Morsy vowed to respond to the attack. Addressing Egyptians on Sunday, Morsy said that he gave clear orders to security leadership to control Sinai and chase the assailants wherever they are.

“You will soon see how we will respond to that criminal attack,” he added.

Shafiq, who lost to Morsy in the presidential run-offs, added that the attack demonstrates that he was right about making Sinai a priority in his election platform. Shafiq blamed the attacks on extremism and weak security, exacerbated by the support extremist groups in Sinai receive from non-Egyptian groups at the border. He said those groups seek to achieve their interests at the expense of national security.