CAIRO — An Egyptian militant group has claimed responsibility for twin suicide bombings that killed three people and wounded eight on Friday in the southern Sinai Peninsula.

In a statement posted Sunday on militant websites, al-Qaeda inspired group Ansar Bayt al-Maqdis warned the Egyptian army “we will not rest until we achieve retribution for the blood and honor of the Muslims.”

In the first attack, a suicide bomber blew himself up in front of a bus carrying workers, killing one and wounding three. Another bomber blew himself up at an army checkpoint, killing a soldier and a civilian passer-by and wounding five others.

The group urged the Egyptian people to “rebel against this oppressive and tyrannical regime” and not resort only to peaceful opposition movements.

The attacks came ahead elections scheduled for later this month, in which Abdel-Fattah el-Sissi, the now-retired army chief who led last summer’s overthrow of Islamist President Mohammed Morsi, appears poised to win on a wave of nationalistic fervor. Posters by his supporters around Cairo tout el-Sissi as a strongman in “the fight against terror” – a reference to a wave of Islamic militant attacks that have escalated since Morsi’s ouster.

The violence first flared in Sinai, where several al-Qaeda-inspired groups have long operated, but in past months it has moved into Egypt’s heartland in the Nile Delta and into the capital, Cairo – mainly in form of crude but often lethal bombings of positions of police or soldiers.

Militant groups have said the attacks are in retaliation for the ferocious security crackdown since Morsi’s ouster that has killed hundreds of his Islamist supporters and arrested thousands more.

Morsi’s backers have continued in protests against the interim government, often leading to bloodshed. On Friday, clashes erupted between Morsi supporters and locals backing security forces in Cairo and the country’s second largest city, Alexandria, leaving two protesters dead and five wounded, according to security officials. The officials spoke on condition of anonymity as they weren’t authorized to brief journalists. The Interior Ministry said that police arrested 42 people during protests across the country in the course of the day, 27 of them in Alexandria.

The government accused Morsi’s Muslim Brotherhood of orchestrating the violence, a claim the group denies, though there have been warnings even by some Islamists that the fierce crackdown on protesters could push young Morsi supporters into acts of violence.