MENA quoted an unidentified security official saying that today's explosion targeted an armored personnel carrier in the city of el-Arish, wounding another 8 policemen.
The official says the wounded were taken to the military hospital in el-Arish.
There was no immediate claim of responsibility for the latest attack. A local affiliate of the Islamic State group has claimed responsibility for a series of attacks on security forces in Sinai since 2014.
Egypt has for years been fighting a Sinai-based Islamic insurgency. The attacks have grown more frequent and deadlier since 2013, when President Abdel-Fattah el-Sissi, then the defense minister, led the ouster of Islamist President Mohammed Morsi.