The military insisted it was acting in response to the massive demonstrations calling for Morsi's ouster, but the West expressed unease over the fact that Egypt's first democratically elected leader has been overthrown a year after taking power.

US President Barack Obama said he was "deeply concerned" over Morsi's overthrow and urged a quick return to elected civilian government.

"We believe that ultimately the future of Egypt can only be determined by the Egyptian people," Obama said in a statement after emergency talks in the White House with top aides.

"Nevertheless, we are deeply concerned by the decision of the Egyptian Armed Forces to remove President Morsi and suspend the Egyptian constitution." He said had ordered a review of the legal implications for US aid to Egypt in the wake of the military's toppling of the elected leader.

In May, Washington renewed its $1.3 billion in annual military aid to Egypt. The army toppled Morsi after a week of bloodshed that killed nearly 50 people as millions took to the streets to demand an end to his turbulent single year of rule.

On Wednesday, Washington ordered most of its embassy staff in Cairo evacuated. EU foreign policy chief Catherine Ashton meanwhile condemned the bloodshed and called for a swift return to democracy.

"I urge all sides to rapidly return to the democratic process, including the holding of free and fair presidential and parliamentary elections and the approval of a constitution," she said.

She expressed hope that the transitional administration announced by the new regime would be fully inclusive and that human rights and the rule of law would be respected.

"I strongly condemn all violent acts, offer my condolences to the families of the victims, and urge the security forces to do everything in their power to protect the lives and well-being of Egyptian citizens," said Ashton.

A senior member of the Muslim Brotherhood said the army was holding the deposed president and several top aides under house arrest. Adly Mansour, the newly appointed head of the Supreme Constitutional Court, has been named interim president.

Britain expressed concern at the latest developments."The situation is clearly dangerous and we call on all sides to show restraint and avoid violence," said Foreign Secretary William Hague.

"The United Kingdom does not support military intervention as a way to resolve disputes in a democratic system," Hague said in a statement.

He called for "early and fair elections which all parties are able to contest, and civilian-led government." A Canadian foreign ministry spokesman called for calm, for dialogue between the rival parties and a return to democracy.

But Saudi King Abdullah on Wednesday praised the army's intervention and congratulated the new caretaker president Mansour.

"We call on God to help you bear the responsibility to achieve the hopes of our brotherly people in Egypt," the head of the Sunni-ruled oil powerhouse said in his message.

Islamist Sudan said Wednesday it hoped for peace and stability in its "sister" country Egypt, official media reported.

Khartoum was following developments with concern in the hope "that peace and stability shall prevail," the state SUNA news agency said, citing a foreign ministry statement.