Authorities in Egypt have grounded several metro lines in Cairo after finding unexploded bombs on the tracks in a station.

Egyptian security officials in the capital said on Thursday that bomb experts were sent to Helmeyet el-Zaytoun station in northeast Cairo to search the tracks for more possible explosive devices.

Explosives experts had earlier found two bombs 100 meters from the station and defused them.

Egypt has been facing insecurity since the ouster of President Mohamed Morsi by the army on July 3. Militant groups have also stepped up their attacks on members of Egyptian security forces ever since.

The surge in violence prompted Cairo to launch a major offensive against the militants and send thousands of troops backed by tanks and heavy equipment into the Sinai Peninsula.