Cairo: Six soldiers were killed Saturday in a dawn attack on their security checkpoint, the army said, blaming the raid on the now-outlawed Muslim Brotherhood.

“At 5am, an armed group belonging to the terrorist Muslim Brotherhood attacked a checkpoint manned by military police in the area of Mustrud [in northern Cairo],” the army said on its official Facebook page.

It added that military explosives experts defused two bombs planted by the assaults next to the checkpoint targeting further troops.

“The Armed Forces vow that these cowardly operations will just increase our determination to continue fighting terrorism.”

The attack comes two days after one army soldier was killed and three others injured in an assault on a military minibus in the eastern Cairo district of Al Amirya.

Security forces have been the target of a string of attacks since July last year when the army deposed president Mohammad Mursi of the Brotherhood in the wake of wide street protests against his one-year rule.

“We have to expect more such terrorist operations as the presidential elections come closer,” said Mamdouh Abdul Halim, a security expert.

“Having failed to derail the vote for constitution [held in January], those terrorists who either belong to the Brotherhood or being sponsored by it, aim at disrupting preparations for the presidential elections. They also want to demoralise security forces.”

The constitutional vote and presidential polls, expected in mid-May, are two milestones of a transitional roadmap announced following Mursi’s ouster. The formula also provides for parliamentary polls expected later this year.

Defence Minister Abdul Fattah Al Sissi is widely tipped to be the lead contender in the presidential elections.

In December, the military-backed government designated the Brotherhood as a terrorist organisation, a label dismissed by the 86-year-old group as politically motivated.

Leaders of the group are either in jail allegedly for inciting violence or have fled Egypt.