Lobna Tarek, Associated Press
Mourners carry the coffin during a funeral for Maj. Gen. Mohammed El-Said, an aide to the interior minister, who was killed gunmen on a motorcycle shot and killed a senior police officer as he left his home in the Haram district of Giza, Egypt, a neighborhood near the Pyramids, Tuesday, Jan. 28, 2014. In increasing attacks against police in the capital, gunmen killed an aide to the country’s interior minister, in a high-profile drive-by shooting. Before the trial was adjourned, gunmen also shot and killed a policeman guarding a church in south Cairo.

EL-ARISH, Egypt — Egyptian helicopters launched airstrikes targeting an al-Qaida-linked group in villages in the north of the Sinai Peninsula overnight, a military spokesman said Friday. He said seven militants were killed and dozens of houses and huts used as hideouts were destroyed.

A long-running military offensive against Sinai-based militants was stepped up after militants shot down a helicopter earlier this week, killing all its crew members. The al-Qaida-inspired Ansar Beit al-Maqdis, or Champions of Jerusalem, claimed responsibility and posted a video of a fighter shooting and hitting a helicopter with a shoulder-fired missile.

Most of the northern Sinai is off-limits to journalists and claims cannot be independently verified.

Ansar attacks surged after the military toppled Islamist President Mohammed Morsi in a July coup that followed millions-strong demonstrations calling on him to leave office.

The government has claimed that Morsi's Muslim Brotherhood is orchestrating the violence, and has designated it a terrorist organization. The group denies any link to the attacks.

The Ansar-led wave of suicide bombings, drive-by shootings and assassinations of senior security officers in the country is a level of violence unseen since the 1990s, when Islamic radicals waged an insurgency concentrated in southern Egypt.

In its latest statements Thursday, Ansar claimed responsibility for this week's assassination of a senior police officer in Cairo and the bombing of a pipeline in the Sinai.

Maj. Gen. Mohammed el-Said was shot to death as he left his home in the Haram district of Giza, a neighborhood near the Pyramids, on Tuesday. He was an aide to the interior minister and head of the technical office in ministry, which is in charge of police. The statement by the militant group described el-Said as "a renegade criminal" and warned the Egyptian military and police leaders to expect more attacks, telling them, to "await the worst as the time of punishment is close."

Separately, Ansar Beit al-Maqdis said it blew up a natural gas pipeline on Monday night south of the North Sinai city of el-Arish. The attack, it said, was part of its war against the "Egyptian regime's economy." The authenticity of the statements could not be independently verified but they were posted on websites commonly used by militants. Gas pipelines have repeatedly come under attacks since the 2011 anti-Mubarak uprising and the security vacuum that ensued.

The Friday overnight strikes in the Peninsula were concentrated in the southern part of Sheikh Zuweyid town near the border of the Gaza Strip, a hub for Islamic militants, said Col. Ahmed Mohammed Ali, military spokesman on his official Facebook page. The helicopters targeted houses, vehicles and stores used for making explosives.

Officials said that the military will intensify the bombings of militants' hideouts in response to the helicopter crash and after investigation showed that two Egyptians and four Palestinians were involved in the attack. They spoke on condition of anonymity because they were not authorized to speak to the press.

Meanwhile, in the capital, Interior Ministry spokesman Hani Abdel-Latif said two planted explosive devices detonated on Friday as a troop carrier drove by with riot police near Giza. One officer was wounded in the attack, which also damaged the front window of the vehicle, said Abdel-Latif.

The ministry also said that security forces shot dead a minibus driver who tried to ram into a checkpoint in the Six of October district outside Cairo. It says troops opened fire on the vehicle when the driver ignored warning shots, killing him, wounding one of the passengers and arresting three other people. The ministry said it is investigating the case.

Across the country, anti-riot police fired tear gas and clashed with hundreds of Morsi supporters in Cairo, Alexandria and Fayoum.

Youssef reported from Cairo.