Protest in Tehran after Saudis hang Shiite cleric Nimr al-Nimr, 46 others - Saudi Arabia on Saturday confirmed that it had executed 47 people in a single day, including a prominent dissident Shiite cleric, Nimr al-Nimr, who was convicted for speaking out against the government and the Saudi royal family.

Nimr had been convicted of inciting sectarian strife, sedition and other charges after his arrest in 2012.

Iran protested the executions and summoned the Saudi ambassador in Tehran to condemn the execution, the state-run IRNA news agency reported. A statement was also issued by the Shiite-majority nation deploring the execution and warning that Saudi Arabia would pay a heavy price for its policies.

"The execution of a personality such as Sheikh Nimr who had no means other than speech to pursue his political and religious objectives only shows the depth of imprudence and irresponsibility," Press TV cited Foreign Ministry spokesman Hossein Jaberi as saying.

Protesters gather outside the Saudi Embassy in Tehran to protest the execution. For its part, Saudi government defended the move saying it executed "terrorists" and told Iran to stay out of its internal affairs.

Saudi Arabia, which "has summoned the Iranian ambassador to the Kingdom today and handed him a strong-worded protest note on the aggressive Iranian statements issued in response to the Islamic rulings carried out on terrorists in the Kingdom," state-run SPA news agency reported.

"During the meeting (in Riyadh), the (Foreign) Ministry expressed the Kingdom's denunciation and categorical rejection to such aggressive statements, which it considers a flagrant violation into the Kingdom's internal affairs," SPA said.

Human rights group Amnesty International denounced the e charges against Nimr vague and pronounced his death sentence "appalling."

"We are particularly concerned that the execution of (al-Nimr) risks exacerbating sectarian tensions at a time when they urgently need to be reduced," US diplomat John Kirby said.