* Militants active since army ousted Mursi a year ago
* New president Sisi says fighting war on terror
* Security crackdown criticised by Western governments (Adds new statement by the militant group of Ajnad Misr)
By Maggie Fick
CAIRO, June 30 (Reuters) - Two Egyptian policemen were killed on Monday trying to defuse bombs planted near Cairo's presidential palace by militants days before the anniversary of the army overthrow of an elected Islamist president.
Radical Islamists have repeatedly attacked police and soldiers with bombings and shootings since the ousting of President Mohamed Mursi of the Muslim Brotherhood. The Brotherhood denies any link to the violence.
The violence was met by a crackdown on Islamist politicians, activists and street protesters of whom thousands were jailed and hundreds were killed.
The militant group Ajnad Misr, or Soldiers of Egypt, claimed responsibility for the blasts in a statement dated Monday.
"God had helped us to make our plan succeed in dragging the security officials to the trap made for them at Itahadiya (presidential) palace," it said on its Twitter account.
"Our targeting of the fortress of their slaughterer shows how easy of a target he, his headquarters and personnel are and that such regime could fall," it said.
Ajnad Misr said last week it had planted several bombs near the presidential palace to target security forces before realising that civilians could be in danger. It said it has been unable to remove the devices and urged passersby to be cautious.
One police officer was killed as security forces tried to deactivate a bomb found at that location, and a second officer was killed during a similar operation in a nearby street, the interior ministry said in a statement.
Monday was the first anniversary of mass street protests against Mursi that led to his removal by the military on July 3. A fierce security crackdown on Islamists ensued and the then-army chief, Abdel Fattah al-Sisi, was elected president in May.
In a televised address to the nation to commemorate the events of a year ago, Sisi used the term "black terrorism" to describe the threats facing Egypt.
"On this day... the first anniversary of the June 30 revolution, black terrorism is still trying to stand in front of the will of Egyptians and their hopes and aspirations," he said in remarks apparently prerecorded at the palace near the site of the explosions.
Egyptian authorities have made no distinction between Islamist militants and the Brotherhood, which they have declared a terrorist organisation.
Thousands of Brotherhood leaders including Mursi and supporters have since been arrested, scores sentenced to death and hundreds more have been killed in a campaign to wreck Egypt's oldest Islamist movement.
Eight people were hurt in a series of explosions last week on Cairo's metro, the first attacks in the capital since Sisi was sworn in as president.
The foreign ministry said on Monday 255 policemen have been killed in militant attacks since last August.
"WAR AGAINST TERRORISM"
The security dragnet has been expanded to include secular and liberal activists, including many who played leading roles in the 2011 popular revolt that ousted autocratic President Hosni Mubarak.
The right to protest has been sharply restricted by a law passed after Mursi's fall last year. Around 23 activists were arrested last week over a rally in Cairo against the law.
Western governments and rights groups have voiced concern for freedom of expression in Egypt. The security clampdown has dimmed hopes for democratic evolution in Egypt that had soared after the anti-Mubarak uprising three years ago.
The jailing last week of three Al Jazeera journalists for seven years on charges of assisting banned Islamists caused an international outcry, which Cairo rejected as interference.
For the United States, concern over human rights issues are balanced by the importance to it of Egypt as a strategic partner in the Middle East.
Sisi, who resigned from his post as army chief in order to run for president, has urged the United States to provide military equipment to Egypt in its campaign against militants.
U.S. Secretary of State John Kerry said during a visit to Cairo earlier this month that Egypt would be given aid in the form of Apache helicopters to use against militants active in the Sinai Peninsula that borders Israel. (Additional reporting by Ali Abdelaty and Stephen Kalin; Editing by Lin Noueihed and Tom Heneghan)