Ansar Beit al-Maqdis (Partisans of Jerusalem) has orchestrated a string of attacks to avenge a deadly government crackdown on supporters of ousted president Mohammad Mursi.
The Al-Qaeda-inspired group posted a video late Tuesday on Twitter showing the bombing hours earlier of a security convoy on a road between the North Sinai provincial capital El-Arish and Rafah on the Gaza border.
An armored personnel carrier (APC) is seen flying into the air while a militant shouts "Allahu Akbar (God is greater)".
The video was also posted on YouTube along with the group's logo of a black flag, an AK-47 assault rifle.
Hundreds of police and army personnel have been killed by extremists since Mursi's ouster, according to the authorities.
The group claimed a bombing earlier this month in Sinai that killed 11 policemen. It also recently expressed support for the Takfiri group, ISIL that has seized swathes of Iraq and Syria.