Police on Sunday arrested 40 protesters after a raid on the Saudi embassy in Teheran on Saturday night, according to the prosecutor-general in the Iranian capital.

Abbas Jafari Dolatabadi was quoted by Iran's Labor News Agency as saying that the judiciary had issued an order to identify and arrest others involved in the embassy raid.

Iranian protesters attacked the embassy after the execution of a Shiite leader by Saudi Arabia. The attack came hours after the Saudi Interior Ministry announced that prominent Shiite leader Nimr al-Nimr and 46 other men had been executed on terror charges.

The Iranian Foreign Ministry urged police on Saturday to protect the diplomatic compounds of Saudi Arabia in Iran.

Earlier in the day, the ministry summoned the Saudi charge d'affaires to Iran and strongly condemned the execution of al-Nimr.

Hours after the protesters stormed the embassy, Iran's top leader warned Saudi Arabia of "divine revenge" over the execution of the cleric, while Riyadh accused Teheran of supporting terrorism.

Iran's Supreme Leader Ayatollah Ali Khamenei condemned the execution on Sunday in a statement on his website, saying al-Nimr "neither invited people to take up arms nor hatched covert plots. The only thing he did was public criticism".

The Saudi Foreign Ministry said that by condemning the execution, Iran had "revealed its true face represented in support for terrorism".

United Nations chief Ban Ki-moon's spokesman said Ban was "deeply dismayed over the execution by Saudi Arabia of 47 people".

Deploring the violence outside the Saudi embassy in Teheran, he called for calm and restraint and urged "all regional leaders to work to avoid the exacerbation of sectarian tensions", the spokesman said in a statement.

Xinhua - AP - AFP