A fresh round of intense diplomatic efforts are underway in Egypt to broker a peaceful end to the crisis sparked by the military's overthrow of Islamist president Mohamed Morsi.
The European Union's Middle East envoy Bernardino Leon and US Deputy Secretary of State William Burns have extended their stay in Cairo to hold a series of talks with Morsi supporters and members of the army-backed interim leadership that replaced him.
Leon met Prime Minister Hazem al-Beblawi on Monday after talks the day before with the number two of Morsi's Muslim Brotherhood movement, Khairat al-Shater, in prison.
A spokeswoman for the State Department in Washington said that Burns and Leon had visited Shater on Sunday, accompanied by the foreign ministers of regional US allies Qatar and the United Arab Emirates.
The spokeswoman, Marie Harf, said the visit was intended to "prevent further violence, calm tensions and facilitate an inclusive dialogue among Egyptians that can help the transition to a democratically elected civilian government".
However, Morsi's deputy gave the delegation a cold shoulder, according to Muslim Brotherhood spokesman Gehad al-Haddad.
Shater refused to discuss the situation with the envoys, saying only that the Brotherhood's position on defending Morsi's legitimacy was "unchanged".
Egypt has been rocked by sometimes deadly political violence after the military ousted Morsi, the country's first democratically elected leader, on July 3.
Morsi supporters see his overthrow as a violation of democracy and insist on nothing short of his reinstatement.
They have staged protest sit-ins that have paralysed parts of the capital and further polarised an already deeply divided country.
More than 250 people have been killed since Morsi's ouster.
Morsi himself has been formally remanded in custody on suspicion of offences committed when he escaped from prison during the 2011 revolt that toppled former president Hosni Mubarak.
In a renewed push to find a solution to the crisis, US senators John McCain and Lindsay Graham were expected to begin a fresh round of shuttle diplomacy in Cairo on Tuesday.
In recent days, EU foreign policy supremo Catherine Ashton, Arab diplomats, an African delegation and German Foreign Minister Guido Westerwelle have all travelled to Cairo in a bid to defuse the crisis.
