U.S. Secretary of State John Kerry said Monday he supported bringing perpetrators of the attempted coup in Turkey to justice, but warns the government against going "too far" while restoring order in the country.
"We stand squarely on the side of the elected leadership in Turkey," he told a news conference after meeting EU counterparts in Brussels. "But we also firmly urge the government of Turkey to maintain calm and stability throughout the country."
"We also urge the government of Turkey to uphold the highest standards of respect for the nation's democratic institutions and the rule of law," he continued. "We will certainly support bringing the perpetrators of the coup to justice but we also caution against a reach that goes well beyond that."
WATCH: Kerry discusses Turkey coup attempt
State-run news agency Anadolu reported that 8,777 officers have been suspended and 6,000 members of the judiciary and military have been detained following the attempted coup Friday, sparking concern from world leaders who warn against actions that would damage constitutional order.
EU foreign policy chief Federica Mogherini said the rule of law "needs to be protected for the sake of the country." She made the comment at a meeting of EU foreign ministers in Brussels Monday.
Turkish President Recep Tayyip Erdogan has promised to rid Turkey of people involved in the coup attempt. "At every level of government, the period of cleaning this virus will continue," said Erdogan. "Like the cancer virus, it spreads all around the government."
State-run media report an aide to Erdogan is among those in custody, and a warrant has been issued for the arrest of Erdogan's top military aide, Colonel Ali Yazici. It was not immediately clear what role, if any, Yazici had in the failed coup attempt.
Justice Minister Bekir Bozdag says Turkish authorities are accelerating arrests of people, which have included judges, military officers and soldiers. Those in custody include the commander of the Third Army Corps, General Erdal Ozturk, who could face charges of treason.
Other high-ranking military officials flew to neighboring Greece by helicopter and requested political asylum. Turkish media reports say some of those who fled are believed to be among the architects of the coup
Death penalty considered
Speaking Sunday to people who called for the death penalty outside his home in Istanbul, Erdogan said the use of capital punishment cannot be delayed, saying "We cannot ignore this demand."
His speech was punctuated by frequent calls of "we want the death penalty'' from the large crowd, to which Erdogan responded: "We hear your request. In a democracy, whatever the people want they will get.''
Erdogan said he would discuss it with opposition parties but that "We will not delay this decision for long. Because those who attempt a coup in this country must pay.''
Turkey hasn't executed anyone since 1984, and capital punishment was legally abolished in 2004 as part of Turkey's bid to join the European Union.
Austrian foreign minister Sebastian Kurz said the reintroduction of the death penalty would be "absolutely unacceptable" in an interview with state media ahead of his meeting with his European counterparts Monday.
Kerry denies US Involvement
Secretary Kerry has denounced suggestions that Washington was involved in Friday's failed coup in Turkey.
"We think it's irresponsible to have accusations of American involvement," Kerry told CNN on Sunday.
Turkish President Erdogan has accused Fethullah Gulen, a reclusive cleric now living in Pennsylvania, of orchestrating the violence and demanded that Gulen be extradited.
WATCH: Muslim Cleric Gulen Denies Claims of Coup Involvement
Erdogan frequently refers to "masterminds" who he says are bent on breaking up Turkey, in what appears a veiled reference to the West in general, and more specifically, the United States. On Saturday, Labor Minister Suleyman Soylu accused Washington of being behind the coup attempt.
In a phone call on Saturday Kerry told Turkish Foreign Minister Mevlut Cavusoglu “public insinuations or claims about any role by the United States in the failed coup attempt are utterly false and harmful to our bilateral relations,” according to a report of the call released by the State Department.
Kerry also told CNN that Turkey has made no formal request for Gulen's extradition, and that he'd asked the country's foreign minister to make the official request, saying that "the United States is not harboring anybody."
Gulen has denied being behind the failed coup and denied knowledge of who might be responsible.
Meanwhile, thousands of people attended funerals Sunday in Istanbul and Ankara for those killed. Prayers were read simultaneously from Turkey's 85,000 mosques at noon to honor those who died.
Erdogan openly wept Sunday at the funeral for his top campaign manager and the manager's teenage son who were killed when renegade soldiers opened fire on protesters at the Bosporus bridge in Istanbul on Friday night.
He used a handkerchief to wipe away the tears and turned around as he continued to weep.
Reports about how many people were killed in clashes during the coup attempt varied, but by Sunday 265 were reported dead, including many civilians. Conditions remained tense in Istanbul, Ankara and some other provincial cities, and there were reports of sporadic violence.
US military operations
Turkey on Sunday also reopened its airspace to military aircraft, allowing the U.S.-led coalition to resume air operations against Islamic State militants.
Turkey had closed its airspace following the attempted coup.
Turkey, a NATO member, is a key partner in U.S.-led efforts to defeat the Islamic State group and has allowed American jets to use its Incirlik air base to fly missions against the extremists in nearby Syria and Iraq.
VOA's National Security Correspondent Jeff Seldin, White House Correspondent Mary Alice Salinas, VOA's Turkish service, Georgian service, and reporters Ken Schwartz and Isabela Cocoli are among those who contributed to this story.