Egypt must release jailed Muslim Brotherhood leaders to help resolve a political crisis following the overthrow of President Mohamed Morsi, Qatar's foreign minister has said in an interview with Al Jazeera.
Khaled al-Attiya, one of the latest foreign envoys to try and mediate an end to the political turmoil in Egypt, returned to Doha on Wednesday after several days in Cairo and complained he had not been able to meet all the parties he had been promised to see.
Morsi, Egypt's first democratically elected president, was ousted on July 3, following large protests and is now detained at an undisclosed location as thousands of his supporters camp out at two protest sites in Cairo.
"My wish for the brothers in Egypt is to release the political prisoners as soon as possible because they are the key to unlocking this crisis," he said.
"Without a serious dialogue with all the parties, and most importantly with the political prisoners because they are the main element in this crisis, I believe things will be difficult."
Qatar had been the main supporter of Egypt under Brotherhood rule, giving the Arab country about $7bn in aid before Morsi was ousted, Reuters reported.
Attiya said he had met jailed Brotherhood deputy leader Khairat El-Shater for an hour and a half. He also met interim Vice President Mohammed ElBaradei, but was not able to see Morsi or army chief General Abdel Fattah El Sisi.
He said there had been an agreement that he would be able to meet all parties "but our luck allowed us only to meet with engineer Khairat El-Shater during this visit".
On Tuesday, US senators John McCain and Linsdsey Graham said they considered Morsi's removal to have been a military coup - causing an uproar in the Egyptian media and drawing a strong riposte from the acting president.
McCain said Egypt could turn into "all-out bloodshed" in the coming days if efforts to find a political solution fail.
"These folks are just days or weeks away from all-out bloodshed," the senator added.
Morsi's deposal has led to violent confrontations between military forces and supporters of the overthrown leader.
During the CBS News interview, McCain, who unsuccessfully ran for US president in 2008, said: "There is only one way to bring about a peaceful Egypt and that is the process of negotiation and reconciliation between the major players".
Thousands of Morsi's supporters remain camped out at two protest sites in Cairo, which the government has pledged to break up.
Almost 300 people have been killed in political violence since he was toppled, including 80 shot dead by security forces in a single incident on July 27.
The interim leadership says there is no turning back on the army-drafted roadmap that calls for new elections in 2014.