As diplomats arrived home after being told to leave Saudi Arabia, Shia-dominated Iran fired the latest verbal salvo in a dispute that has seen Riyadh and some Sunni Arab allies cut diplomatic ties with Tehran.
At a press conference in the capital, Foreign Minister Mohammad Javad Zarif said Riyadh must end prolonged efforts to confront Iran.
Citing longstanding differences that became a full-blown split after Saudi Arabia executed Shia cleric and activist Nimr al-Nimr, Zarif said the Sunni-ruled kingdom had sought systematically to inflict damage.
"For the past two-and-a-half years, Saudi Arabia has opposed Iran's diplomacy," he said at the press conference with Iraqi Foreign Minister Ibrahim al-Jaafari.
"Saudi Arabia has moved against our efforts and, unfortunately, they opposed the nuclear agreement," Zarif said, also accusing Riyadh of "taking measures against the Iranian people" through its efforts to keep oil prices low.
"This trend of creating tension must stop. We need to stand united... and stop those who are adding fuel to the fire," he added.
Nimr's death sparked demonstrations in many countries including Iran, where protesters stormed and set fire to the Saudi embassy in Tehran as well as the kingdom's consulate in second city Mashhad.
Riyadh cut ties with Tehran in response and was joined by some of its Sunni Arab allies including Bahrain and Sudan. The United Arab Emirates also downgraded relations with Iran and Kuwait recalled its ambassador.
Staff at Iran's embassy in Riyadh and its consulate in Jeddah flew home Wednesday, Saudi state news agency SPA reported.
Iran's state broadcaster IRIB said a plane carrying 54 Iranian diplomats and their families had landed at Tehran's Mehrabad Airport.
The dispute has raised fears of an increase in sectarian tensions in the Middle East that could derail efforts to resolve pressing issues including the wars in Syria and Yemen.
The United Nations and Western governments have expressed deep concern, urging both sides to reduce tensions.
US Secretary of State John Kerry has made repeated calls to both Iranian and Saudi leaders.
"He is urging calm. He is stressing the need for dialogue and engagement, and thirdly, reminding that, again, there's lots of work to be done in the region," State Department spokesman John Kirby said Tuesday.
Saudi Arabia and Iran are on opposing sides in some of the Middle East's worst conflicts.
In Syria, Iran is supporting the government of President Bashar al-Assad against rebel groups, some backed by Saudi Arabia.
And in Yemen, Riyadh is leading a military intervention against Iran-backed Shia rebels who have seized control of large parts of the country.
Iran-linked 'terror' cell
Within hours of the embassy attack, Iran's President Hassan Rouhani called the violence "totally unjustified" but accused Saudi Arabia Tuesday of focusing attention on the incident to "cover its crime" of executing Nimr.
Zarif reiterated that the embassy's ransacking had no official blessing. "All Iranian officials condemn it," he said.
Jaafari, who was to also hold talks with Rouhani, said Iraq was seeking a potential diplomatic role to help resolve the crisis and echoed the concerns about sectarianism.
"I have spoken to the foreign ministers of some of the Arab countries to reduce the consequences of this issue and prevent enemies from dragging the region into a war that can have no winners," Jaafari said.
Shia-majority Iraq has close ties with Tehran.
In a further sign of tensions, Sunni-ruled but Shia-majority Bahrain said it had dismantled an Iran-linked "terror" cell that was planning attacks in the kingdom.
The cell was allegedly linked to Iran's Revolutionary Guards and Lebanon's Tehran-backed Hezbollah militia and planning a "series of dangerous bombings" on the tiny Gulf kingdom, the interior ministry said.
Nimr, one of 47 men executed Saturday, was a driving force behind 2011 anti-government protests in Saudi Arabia's Eastern Province.
He was arrested in 2012 after calling for two governorates to be separated from the kingdom.
Riyadh has said the executions were an internal security matter, and among those put to death were many Al-Qaeda-linked militants convicted of attacks in the kingdom.
