Xinhuanet.com :An Iranian official says 40 people have been arrested after Saudi Arabia’s embassy was attacked and set on fire following outrage at the kingdom’s execution of a Shiite cleric, Nimr al-Nimr.The ISNA news agency quoted Tehran prosecutor Abbas Jafari Dolatabadi, saying that the suspects were identified and arrested and other detentions could follow.The ISNA said demonstrators massed at the embassy gates and later broke into the embassy and started fires before being cleared away by the police. Iran’s Foreign Ministry issued a statement shortly afterwards, calling for calm and urging protesters to respect the diplomatic premises.Iranian Supreme Leader Ayatollah Ali Khamenei, attacking Saudi Arabia for a second day, said Saudi politicians would face divine retribution for Nimr’s death. Iran’s Revolutionary Guards said the execution would lead to the downfall of the Saudi regime.