Egypt violence 'serious blow' to peace efforts but no change in US policy Secretary of State John Kerry gestures during a statement on the ongoing situation in Egypt before the start of a press briefing at the State Department in Washington. Washington: In a stern warning to Egypt's leaders, Secretary of State John Kerry said the escalating violence throughout the country on Wednesday had dealt a "serious blow" to political reconciliation efforts between the military-backed interim government and supporters of ousted President Mohamed Mursi. Mr Kerry insisted that a political solution remains a viable option in Egypt Mr Kerry, during a surprise appearance at the State Department, condemned the violence that killed at least 149 people nationwide and the reinstatement of emergency rule. He urged Egypt's interim leaders to take a step back and calm the situation. Wednesday's assault came after days of warnings by the interim administration that replaced Dr Mursi after he was ousted on July 3. The two sit-in camps at two major intersections on opposite sides of the Egyptian capital began in late June to show support for Dr Mursi. Protesters - many from Dr Mursi's Muslim Brotherhood - have demanded his reinstatement. Vice President Mohamed ElBaradei, a Nobel Peace Prize laureate and pro-reform leader in the interim government, resigned in protest over the assaults as the military-backed leadership imposed a monthlong state of emergency and nighttime curfew. Mr Kerry spoke earlier on Wednesday with Egypt's foreign minister, as well as other top officials in the Middle East. He insisted that a political solution remains a viable option in Egypt, though he conceded that path was made "much, much harder" by the recent events. President Barack Obama, on a weeklong vacation in Martha's Vineyard, Massachusetts, was briefed on the deteriorating situation by national security adviser Susan Rice. White House and State Department officials said the US role was largely to encourage the interim government to fulfil its promises to enact political reform. The military-backed government has pledged to amend the Islamist-backed constitution adopted last year and holding parliamentary and presidential elections early next year. "Figuring out how to encourage the interim government to make good on their promise to transition to a democratically elected government there is something that we're working on," White House spokesman Josh Earnest said. Hopefully it's something they're working on. The turmoil was the latest chapter in a bitter standoff between Dr Mursi's supporters and the interim leadership that took over the Arab world's most populous country. The military ousted Dr Mursi after millions of Egyptians massed in the streets at the end of June to call for him to step down, accusing him of giving the Brotherhood undue influence and failing to implement vital reforms or bolster the ailing economy. Dr Mursi has been held at an undisclosed location. Other Brotherhood leaders have been charged with inciting violence or conspiring in the killing of protesters. At least 250 people have died in previous clashes since the Dr Mursi's overthrow.