DUBAI (Reuters) - Iran’s foreign minister has complained to the United Nations about Saudi Arabia’s “provocations” toward Tehran, as a diplomatic crisis between the region’s two major powers entered its second week.

A protester holds a picture of Shi'ite cleric Sheikh Nimr al-Nimr, who was executed in Saudi Arabia, as others chant slogans during a rally after Friday prayers in Tehran January 8, 2016. REUTERS/Raheb Homavandi

In a letter to the U.N. Secretary-General Ban Ki-moon published by Iranian news agencies on Saturday, Mohammad Javad Zarif said “some people” in Riyadh seemed bent on dragging the whole region into crisis.

The two powers, both major oil exporters, have been locked in a diplomatic battle since Saudi Arabia executed Shi’ite cleric Nimr al-Nimr on Jan. 2. Iranian protesters then stormed the Saudi embassy in Tehran, prompting Riyadh to sever relations.

Zarif said Iran had “no desire” to escalate tensions further, but offered no compromise as he placed the blame for the crisis, and the wider turmoil across the region, squarely on Saudi shoulders.

“They (the Saudis) can continue to support extremist terrorists and promote sectarian hatred, or choose the path of good neighborliness and play a constructive role in regional security,” state news agency IRNA quoted Zarif’s letter as saying in Farsi.

Zarif said Sunni Saudi Arabia had engaged in a series of “direct provocations” toward Shi’ite Iran, including the execution of Nimr and what he described as “persistent mistreatment” of Iranian pilgrims visiting Mecca.

Saudi Arabia says last week’s executions were a domestic matter, and that Iran is the country pursuing sectarian division by casting itself as the champion of Arab Shi’ites.

Zarif also portrayed Saudi Arabia as a threat to regional and global security in the letter, copies of which were sent to the Organization of Islamic Cooperation and the foreign ministers of several countries.

“Most members of al Qaeda, the Taliban, Islamic State and Nusra Front are Saudi citizens or have been brainwashed by demagogues wielding oil money,” IRNA quoted him as writing, in an unusually direct allegation.

Saudi Arabia opposes extremist groups: it executed dozens of al Qaeda members last week alongside Nimr, and last month announced an Islamic coalition against terrorism. But the kingdom’s ultra conservative Wahhabi clergy, which views Shi’ites as heretical, is a cornerstone of Saudi ruling legitimacy.

Riyadh says around 2,500 Saudis have gone to fight in Syria and Iraq, ‎constituting one of the largest groups of foreign fighters, but only a fraction of the total number estimated to be in the tens of thousands.