Egypt's prosecutor-general has ordered the detention of 35 suspects accused of joining terrorist organisations, pending 15 days further investigation.

The suspects were arrested in five different governorates on accusations of joining groups like the Islamic State and planning a series of terrorist attacks in the country.

On Saturday, the interior ministry announced that it had uncovered five alleged terrorist cells in Damietta, Sharqiya, Ismailiya, Beheira and Sohag governorates.

According to the prosecutor-general's statement issued on Sunday, a number of suspects have confessed to travelling as businessmen to Turkey, from where they then headed to Syria in order to join militant groups including IS and receive militant training.

The suspects also allegedly confessed that they returned to Egypt to await further instructions from IS in order to launch a series of attacks against the country's army and police as well as judges and state institutions.

The suspected cells were reportedly recruiting Muslim Brotherhood members who believed in establishing an Islamic caliphate, the statement said.

The Brotherhood was declared a terrorist organisation by Egypt's authorities in late 2013.

According to a Reuters report from September, not less than 1,000 Egyptians are reportedly fighting among IS troops in Syria and Iraq.