Egypt nabs militants over bombs claimed by different group

Just hours before the anniversary of deposed president Mohamed Morsi's military ouster, a small explosion went off near a Cairo military hospital.

The small bomb detonated late Wednesday under the car near an Air Force hospital in a northern neighbourhood in the capital.

The bombing comes as Egyptian police arrested four members of an Islamist militant group over a blast near a presidential palace on Monday which killed two bomb disposal experts as they attempted to defuse them

Separately, the interior ministry said police arrested two people over bombings at Cairo metro stations on 25 June that wounded five people.

Militants have stepped up their attacks against security forces since the army ousted Islamist president Morsi last July and the military-installed authorities launched a deadly crackdown on his supporters. 

Attacks by militants have killed almost 500 police and soldiers since Morsi's overthrow, the government says.

And since then, the country has been roiled by unrest, with a police crackdown killing more than 1,400 Morsi supporters. At least 16,000 others have been jailed, and about 200 sentenced to death.

Those arrested on Wednesday and accused with the presidential palance bombing are "among the most dangerous terrorist elements of Ansar Beit al-Maqdis (Partisans of Jerusalem) and are being interrogated," a security official said.

Three were arrested at dawn in the southern Cairo suburb of Helwan, while the fourth was detained in the capital's Nasr City district, he said.

Sinai-based Ansar Beit al-Maqdis has claimed some of the deadliest attacks in Egypt since the ouster of Islamist president Mohamed Morsi last July.

But the bombs that exploded Monday were actually claimed by another group, Ajnad Misr (Soldiers of Egypt), which had warned on Friday that it had planted them.

It said then that it had not set off the bombs to avoid civilian casualties, and warned passers-by to stay away from the palace.

The authorities claim that groups like Ansar Beit al-Maqdis are linked to Morsi's Muslim Brotherhood, which was blacklisted as "terrorist organisation" in December after a deadly bombing north of Cairo.

The Brotherhood denied that bombing as well as all other attacks, saying it is resorting to only "peaceful protests" in favour of Morsi.

Meanwhile, the interior ministry said Wednesday police arrested two "terrorist elements" who belong to the Brotherhood and were involved in one of the five Cairo metro bombings.

A third suspect was wounded in the explosion at the Shubra al-Kheima metro station and has been under guard in hospital since then.