CAIRO -- Suicide bombers killed at least six soldiers in two separate attacks in Sinai on Wednesday, security officials said, as the new government said it was stepping up its crackdown on Islamist militants there and also appeared to be moving against non-Islamist voices of dissent.
Militants in the relatively lawless northern Sinai have lashed out in deadly attacks on security forces with increasing frequency in the two months since the military ousted President Mohamed Morsi, a leader of the Muslim Brotherhood. Security officials say the attacks have killed scores of soldiers and police officers, including two dozen in a single massacre last month. Some news reports on Wednesday said the latest attacks had killed as many as nine soldiers. They were carried out by two drive-by suicide bombers, at a military intelligence building and a check point, both near the border crossing to Gaza.
The military, in response, has begun a sweeping campaign aimed at clearing Sinai of militants. Military officials say they have killed more than 100, including 29 since Saturday.
In Cairo, meanwhile, members of the left-leaning April 6 group said Wednesday that the police had raided one of their local offices without a warrant and detained several activists for several hours.
The group is admired internationally for its leading role in the largely nonviolent protest movement that brought down President Hosni Mubarak, and the police action against it may be the strongest signal yet that the new government installed by Gen. Abdul-Fattah el-Sisi is moving to quiet other dissenters as well as Islamist supporters of Mr. Morsi.
State news media reports in recent days have suggested that public prosecutors may be reviving investigations of the April 6 group and other liberal or left-leaning activists on suspicions that they collaborated with Western governments beginning in the Mubarak era to stir unrest in Egypt. Government officials denied the reports, but some human rights activists argued that floating the false reports in the state news media was nonetheless a threatening development.
The government on Wednesday also filed charges in a military court against a prominent journalist covering Northern Sinai, Ahmed Abu Deraa, over claims of reporting false information contradicting the army's statements about operations in Sinai, state news media reported. Mr. Abu Deraa was also charged with entering a military-controlled zone without permission.
But like the charges against the April 6 group, his case has become a high-profile test of how far the new government may widen its crackdown beyond Islamists with the goal of quieting other dissenters.
The new government has already taken several Islamist satellite channels off the air, charging them with inciting violence, and ensuring that the only Egyptian channels remaining on the air are supportive of the military takeover.
The government has also detained several journalists from the pan-Arab network Al Jazeera, virtually the only Arabic language channel in Egypt sympathetic to the Islamists, and raided some of its offices.
But the case against Mr. Abu Deraa, who works for an Egyptian newspaper and a satellite network that both generally support the military takeover, has drawn widespread attention here, in part because he is not an Islamist and appears to have been punished for doing his job as a journalist.
After the military announced last week that it had killed a group of militants in a strike on a town in Northern Sinai, Mr. Abu Deraa reported that the attack had killed four civilians instead. Like other claims and counterclaims about the military's Sinai operation, neither the official accounts nor his reports can be confirmed, in part because the military tries to keep journalists out of its area of operations.
A day later, Mr. Abu Deraa visited a state security office in the Northern Sinai to press for the release of a jailed relative. Instead of releasing his brother, however, the police arrested Mr. Abu Deraa, according to a report from the nonprofit media advocacy group Reporters Without Borders, which demanded his immediate release.
The authorities also indicated on Wednesday that they might extend their imposition of a state of emergency, which includes the suspension of most rights afforded criminal suspects, in an effort to protect against police abuse.
The government declared a one-month state of emergency on Aug. 14, the day the police stormed two Islamist sit-ins against the military takeover and killed several hundred protesters. Nighttime curfews are still in effect in much of the country to deter protests, and train service remains shut down around the country to prevent Islamists from converging on Cairo.
In an interview on Wednesday with Al Masry Al Youm, a privately owned newspaper sympathetic to the government, the interim prime minister, Hazem el-Beblawi, said the state of emergency might be extended because of the attempted assassination of the interior minister last Thursday in a bomb explosion on a busy Cairo street. Instead, the explosion killed at least one policeman and one civilian and injured many others.
A hard-line Islamist group, Ansar Bayt al-Maqdis, which is based in Sinai, claimed responsibility for the assassination attempt.
On Wednesday, it also claimed responsibility for attacking several military vehicles and killing at least six soldiers in Sinai, but those reports also could not be independently verified.
This article originally appeared in The New York Times.