CAIRO - Islamic State's Egypt wing claimed a series of attacks that killed at least 27 security personnel on Thursday in some of the worst anti-government violence in months, after commemorations around the anniversary of the 2011 uprising turned deadly in the past week.
Egypt's government faces an Islamist insurgency based in Sinai and growing discontent with what critics perceive as heavy-handed security tactics.
A series of tweets from the Sinai Province's Twitter account claimed responsibility for each of the four attacks that took place in North Sinai province within hours of one another on Thursday night.
Ansar Bayt al-Maqdis, Egypt's most active militant group, changed its name to Sinai Province last year after swearing allegiance to Islamic State, the hardline Sunni militant group that has seized swathes of Iraq and Syria, drawing US-led airstrikes.
Thursday's first attack was a bombing targeting a military headquarters, base and hotel in the capital of North Sinai province that killed 25 and wounded at least 58, including nine civilians, security and medical sources said.
The flagship government newspaper, al-Ahram, said its office in the city of Al-Arish, which is situated opposite the military buildings, had been "completely destroyed," although it was not clear if it had been a target.
Later, suspected militants killed an army major and wounded six others at a checkpoint in Rafah, while an assault on a checkpoint south of Al-Arish wounded four soldiers, security sources said. A roadside bomb in Suez city, not in the Sinai, that killed a police officer was not claimed by IS.
After Sinai Province's claim of responsibility, security sources said a suspected militant had been killed while attempting to plant a bomb at a power transformer in Port Said.
Sinai-based militants have killed hundreds of security officers since President Mohamed Mursi of the Muslim Brotherhood was removed from power following mass protests against his rule.
The military said in a statement on its Facebook page that the attacks were the result of a successful campaign to pressure the militants.
The US State Department condemned the attack, saying in a statement: "The United States remains steadfast in its support of the Egyptian government's efforts to combat the threat of terrorism in Egypt as part of our continuing commitment to the strategic partnership between our two countries."