Egyptian troops have killed 14 fighters in shootouts in the Sinai Peninsula, scene of an insurgency since the overthrow of President Mohamed Morsi last year, according to the army.

It said 47 people were arrested in the clashes on Saturday that state news agency MENA said broke out near Sheikh Zuwaid in north Sinai.

Also on Saturday, four children were killed when a mortar round crashed into their home in El-Joura, a suspected bastion of Islamist fighters.

Officials said the mortar attack apparently targeted soldiers and police combing the area for fighters who had killed two senior officers.

Violent attacks have surged since the army overthrew Morsi, backed by the Muslim Brotherhood, in July 2013 and cracked down on his supporters.

At least 1,400 people have been killed in the crackdown, mostly Islamist protesters.

The attacks usually target security personnel, but they have also led to civilian casualties.

The military has poured armour and soldiers into the peninsula to quell the armed groups, who have also struck Cairo and other cities using car bombs.