At least 12 people, mostly Egyptian policemen, were killed Sunday when militants attacked a police station in the provincial capital of Egypt's northern Sinai, and detonated a roadside bomb against a passing armored vehicle, officials said.
Northern Sinai has witnessed a series of complex and successful attacks targeting Egyptian security forces, many of which have been claimed by a local affiliate of the Islamic State group.
In the largest of the day's attacks, a suspected car bomber detonated his vehicle at the entrance of a main police station in el-Arish, the capital of North Sinai province, killing at least six, including five policemen, and injuring several civilians, the Interior Ministry said.
The blast left a deep crater in the residential area, and damaged several homes nearby. Officials said rescue crews were searching through the rubble for survivors and the death toll was expected to rise.
The explosion was the second attack Sunday on troops in Sinai. Earlier in the day, six soldiers, including an officer, were killed when a roadside bomb struck their armored vehicle traveling south of el-Arish. In a third smaller attack, militants clashed with soldiers at a mobile checkpoint in Rafah, south of el-Arish, wounding one police officer and two soldiers.
Sunday is Eastern Orthodox Easter in Egypt, and police have been on high alert against attacks.
The attacks took place as Egypt's defense minister carried out a limited military reshuffle, replacing the commander of the army division responsible for securing northern Sinai.
Maj. Gen. Mohammed el-Shahat, who only commanded Egypt's second field army for about a year, was promoted to head of military intelligence; el-Shahat's deputy, Maj. Gen. Nasser el-Assi, will replace him.
In a statement posted on its official Facebook page, the Interior Ministry - which oversees the police - said a suicide bomber in a small truck drove through a checkpoint outside the police station, causing guards to open fire before the vehicle exploded. The ministry said five policemen and a civilian were killed in the explosion.
An official said the dead include two ranking police officers and two conscripts.
The officials all spoke on condition of anonymity because they were not authorized to brief reporters.
Residents say the explosion outside one of four main police stations in el-Arish shook the surrounding district. One woman said her house walls cracked. Cars outside the station were on fire.
Abu Mohammed, a resident who lives near the police station, said body parts littered the area after the huge explosion, which also split an armored car into two. He said the suicide bomber kept on driving past sand mounds and a cement blast wall securing the station -- all despite coming under heavy fire from the guards.
"Those at the other end of town heard the explosion. It was humongous. It terrified us," Abu Mohammed said, using an alias for fear of reprisals from the militants. "I am not afraid of them. I only fear for those around me. We will not leave our town until we liberate it from those terrorists."
Health ministry spokesman Hossam Abdel-Ghaffar in Cairo confirmed that the initial rescue efforts pulled six dead, and at least 40 injured, from the scene of the explosion.
The new army commander in the area, el-Assi, inherits the simmering Sinai-based Islamic insurgency that continues to target army soldiers and police officers despite an intensive military campaign. The attacks surged following the 2013 military ouster of Islamist President Mohammed Morsi.
The largest Sinai-based militant group, Ansar Beit al-Maqdis, pledged allegiance to the Islamic State group last year and now refers to itself as the group's Sinai Province. The group claimed responsibility on Twitter for Sunday's roadside bombing, but no one had yet claimed responsibility for the police station attack.
Earlier this month, the IS affiliate in Sinai killed at least 16 soldiers and three civilians and kidnapped a conscript. On Friday they posted a video showing the kidnapped soldier pleading with Egyptians not to join the army before being shot to death.
The reshuffle in military leadership also included the commander of the Egyptian navy at a time when the navy could begin playing an increasingly prominent role, because of the Yemeni crisis. Egyptian warships are already deployed off the coast of Yemen to secure the strategically vital Bab el-Mandab strait - the gateway to the Suez Canal.
Egypt is currently a main member of the Saudi-led military coalition launching airstrikes against Shiite rebels who have conquered the Yemeni capital, Sanaa, and forced out the Western-backed president. Egyptian military leaders have repeatedly stated their willingness to commit ground troops, if necessary, to the operation.