Egyptian troops on Monday killed three militant fighters in shoot-outs in the border Sinai Peninsula, where the military is combating Islamist insurgents, the army said.

Six suspects were also arrested during the raids in North Sinai, army spokesman Mohamed Samir said in a statement, adding that a car and 16 motorbikes used in attacks by the "terrorist elements" were destroyed in the firefight.

Egypt has been hit by an upsurge in Islamist militancy led by Sinai-based fighters that has mainly targeted security forces since the ouster of Islamist president Mohamed Morsi last summer and an ensuing crackdown on his supporters. Militants have also struck Cairo and the Nile Delta with bombings and shootings.

On Sunday, a six-year-old child was killed and four others wounded when a mortar shell smashed into their home in a village in the northern Sinai town of Sheikh Zuweid, Aswat Masriya reported.The attack apparently targeted soldiers and police fighting with suspected militants in the area.

Egypt's military has launched large-scale operations in the underdeveloped region to quell the militants whose attacks have also led to civilian casualties.

At least five children were killed in two North Sinai towns last week in rocket attacks at their homes.