CAIRO — Egypt’s army killed a field commander in Ansar Bayt al-Maqdis, the country’s most dangerous militant group, during clashes on Thursday in the lawless north of the Sinai Peninsula, security sources said.

Mohamed Abu Shatiya, among militants behind the kidnapping of seven Egyptian soldiers in Sinai last year, died during fighting with the army south of Rafah, on the border with Gaza.

Two tons of explosives were confiscated from a nearby tunnel connecting Sinai to Gaza during the incident, they said.

Sinai-based Ansar Bayt al-Maqdis has killed hundreds of Egyptian soldiers and police over the last year and beheaded several people in recent weeks, saying they were spies for Israeli intelligence.

The bloodshed suggests the group, which seeks to topple the government, had become more extreme.

Egyptian security officials have said Ansar Bayt al-Maqdis has contacts with al-Qaeda offshoot “Islamic State.”

They have also highlighted what they say are links between militants in both Libya and Egypt and IS, saying Libyan-based Egyptian militants dream of creating an Islamic State-style empire in their homeland.

Despite several army operations, Egypt’s military has struggled to tackle Ansar and other militant groups.

Washington has designated Ansar a terrorist organization, but says the group generally maintained a local focus.