"In resuming its efforts to eliminate terrorist elements around north Sinai, the air forces, in coordination with the artillery forces, have killed 98 jihadis on Friday," Xinhua quoted military spokesman Mohamed Samir as saying.
The army launched the operation "the martyrs' rights" around the Sinai towns of Rafah, Sheikh Zuweid and El-Arish, which has killed at least 232 militants in four days.
Egypt has been suffering a surge of militant attacks after the ouster of the Islamist president Mohamed Morsi in 2013 by the army, in response to mass protests against his rule.
Most of the attacks, which have killed hundreds of army and policemen, were claimed by Ansar Bayt al-Maqdis group, which has changed its name to "Sinai State" and declared allegiance to the IS group last year.
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In response, the army has launched wide-scale operation to uproot the militants' hideouts in the peninsula since 2013.