AKIPRESS.COM - Four makeshift bombs exploded within minutes of each other at three Cairo metro stations during morning rush hour on Wednesday, wounding at least four people, police and health officials said.

One bomb went off at the station of Ghamra, in central Cairo, while the others occurred at Shubra el-Kheima and Hadayek al-Kobba on the outskirts of the capital, Middle East media report.

The explosive devices were "very primary" and of "low intensity," the official said.

Four people were hurt in the explosions, senior health ministry official Ahmed al-Ansari said.

The attacks come nearly a month after ex-army chief Abdel Fattah Al-Sisi, who led Morsi's ouster, was elected president.

Since Morsi's ouster, a crackdown on his supporters has left more than 1,400 people dead and seen at least 15,000 jailed, while hundreds have been sentenced to death in speedy mass trials that have sparked an international outcry.

Much of the violence is focused in the north of the mainly desert Sinai Peninsula, but militants have extended their reach to Cairo and the Nile Delta, carrying out a series of high-profile assaults in the heart of the capital.

The authorities have blamed Morsi's Muslim brotherhood for the attacks and have listed the Islamist organisation as a terrorist group.