Iran has come under fire from the world's largest Muslim body as a diplomatic war between Tehran and regional rival Saudi Arabia shows no signs of abating.
The Organisation of Islamic Cooperation slammed Iranian "interference in the region" during a meeting of foreign ministers in the Saudi coastal city of Jeddah.
The body also condemned Iranian protesters sacking of Saudi diplomatic missions in the country, which "breached diplomatic norms".
OIC foreign ministers issued a statement saying it "condemns the aggressions against the missions of the Kingdom of Saudi Arabia in Tehran and Mashhad", which it said went against the body's principles and international law.
Iran, which is also a member of the Islamic group, dismissed the OIC's charges, and Lebanon "distanced" itself from the final statement.
Tensions between Iran and Saudi Arabia erupted on 2 January when a senior Shia cleric - Nimr al-Nimr - was beheaded in Riyadh.
Demonstrations erupted in Shia-majority Iran and led to the protesters storming the Saudi missions, which Riyadh claimed was done in acquiescence with Iranian security forces.
Most Gulf countries and some Arab League members also broke ties with Iran at the start of the year.
The OIC - headed by a Saudi secretary general - also said it "rejects and condemns Iran's inflammatory statements" about Nimr's execution "considering those statements a blatant interference in [Saudi] internal affairs".
However, the group also urged calm between Saudi Arabia and Iran and that Islamic countries should end sectarian discourses and look to fight terrorism together.
The 57 state bloc was founded in 1969, and coincided with the rise of Islamism and demise of Arab nationalism in the Middle East.
Several countries with Muslim majorities or large Muslim minorities have had their memberships suspended or blocked including Syria, Russia and India.