Muhamed Sabry, Associated Press
Egyptians gather around the crater following a bombing that struck a main police station in the capital of the northern Sinai province in el-Arish, Egypt, Sunday, April 11, 2015. The explosion comes hours after a roadside bomb killed six soldiers traveling south of el-Arish in an armored vehicle. The region has been hit by an Islamic insurgency by a group that recently pledged allegiance to the Islamic State.

EL-ARISH, Egypt — A suspected car bomb exploded at the entrance of a main police station in the capital of Egypt's northern Sinai province, killing at least six, including a police officer and injuring several civilians, Egyptian officials said.

The officials say the explosion badly damaged the 3-story building. It left a deep crater in the residential area, and damaged several homes nearby. Civil defense forces were looking through the rubble for casualties, the officials said, and the death toll was expected to rise.

The explosion was the second major attack Sunday on troops in Sinai. Earlier Sunday, six soldiers, including an officer, were killed when a roadside bomb struck their armored vehicle traveling south of el-Arish.

The attacks took place 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.

The officials said the driver of the booby-trapped car bypassed security checks outside the police station. The car went off after guards of the station fired at it. It was not clear if the driver detonated his device or if the car bomb exploded because it was struck by bullets. Those killed in the blast include a senior police officer, and five others.

The officials all spoke on condition of anonymity because they were not authorized to brief reporters.

Health ministry spokesman Hossam Abdel-Ghaffar in Cairo said at least 38 were injured in the attack that rocked the neighborhood.

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.

At approximately the same time, a military checkpoint in the town of Rafah, south of el-Arish, came under attack from militants, who fled the scene. One police officer and two soldiers were injured, the 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

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.

Sunday is eastern orthodox Easter in Egypt, and police have been on high alert against attacks.

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.