RIYADH, Saudi Arabia -- Saudi Arabia announced on Saturday it had executed 47 prisoners convicted of terrorism charges, including al-Qaida detainees and a prominent Shiite cleric who rallied protests against the government.
The execution of Sheikh Nimr al-Nimr is expected to deepen discontent among Saudi Arabia's Shiite minority and heighten sectarian tensions across the region.
Meanwhile, the execution of al-Qaida militants convicted over deadly bombings and shootings in Saudi Arabia raised concerns over revenge attacks. The extremist group's branch in Yemen, known as al-Qaida in the Arabian Peninsula, threatened violence against Saudi security forces last month if they carried out executions of members of the global network.
Saudi Arabia's top cleric Grand Mufti Sheikh Abdulaziz Al Sheikh said the executions were carried out in line with Islamic law and the need to safeguard the kingdom's security. He described the executions as a "mercy to the prisoners" because it would save them from committing more evil acts and prevent chaos.
Islamic scholars around the world hold vastly different views on the application of the death penalty in Islamic Shariah law. Saudi judges adhere to one of the strictest interpretations, a Sunni Muslim ideology referred to as Wahhabism.
Influential Shiite figures and groups across the region were swift to condemn al-Nimr's execution, with Saudi Arabia's regional rival Iran describing it as "irresponsible."
Iran's Foreign Ministry spokesman Jaberi Ansari was quoted on the state-owned English-language Press TV warning that the Saudi monarchy would pay a heavy price for its policies. A senior Iranian cleric, Hossein Nouri Hamedani, said in a statement broadcast on state television that the region should expect "both Shiite and Sunni Muslims to react."
In Iraq, influential Shiite militia Asaib Ahl Al-Haq called on the government to reconsider allowing Saudi Arabia to keep its newly reopened embassy in Baghdad; the Saudi embassy was reopened Friday for the first time in more nearly 25 years.
A Saudi lawyer in the eastern region of the kingdom told The Associated Press that in addition to al-Nimr, three other Shiite political detainees were executed Saturday. The lawyer spoke on condition of anonymity for fear of reprisal.
In Lebanon, a top Shiite cleric condemned al-Nimr's execution, describing it as "a grave mistake that could have been avoided with a royal amnesty that would have helped reduce sectarian tensions in the region." Sheikh Abdul-Amir Kabalan, deputy head of the influential Supreme Shiite Islamic Council that is the main religious body for Lebanon's 1.2 million Shiites, said the executions "will have repercussions in the coming days."
The Lebanese Shiite militant group Hezbollah issued a statement calling al-Nimr's execution an "assassination" and a "ugly crime."
The group added that those who carry the "moral and direct responsibility for this crime are the United States and its allies who give direct protection to the Saudi regime and cover its crimes against its (Saudi) people and people of the region."
Anticipating protests in eastern Saudi Arabia, where minority Saudi Shiites are concentrated, Saudi activists there called for peaceful rallies. Small groups of protesters took to the streets in neighboring Bahrain, which has seen low-level violence since 2011 when the tiny island-nation's Shiite majority held mass protests to demand greater rights from the Sunni-led monarchy.
Advocacy organization Reprieve, which works against the death penalty worldwide, said two out of the four Shiite activists executed were teenagers when they were arrested. Reprieve said Ali al-Ribh was 18 years old and Mohammed al-Shuyokh was 19 at the time of arrest in 2012. Both were convicted on charges related to anti-government protests held in eastern Saudi Arabia.
The Interior Ministry announced the names of all 47 people executed in a statement carried by the state-run Saudi Press Agency. Of those executed, 45 were Saudi citizens, one was from Chad and another was from Egypt.
The four Shiites executed had been convicted in connection with a series of violent protests that erupted in the east in 2011 and 2012, in which several protesters and police officers were killed.
The al-Qaida militants executed had been convicted of taking part in a wave of deadly attacks that killed foreigners and Saudis. One of the executed was Faris al-Shuwail, a leading ideologue in al-Qaida's Saudi branch who was arrested in August 2004 during a massive crackdown on the group following the series of deadly attacks.
Saudi Arabia said a royal court order was issued to implement the sentences after all appeals had been exhausted. The executions took place in the capital, Riyadh, and 12 other cities and towns, the Interior Ministry statement said. Nearly all executions carried out in Saudi Arabia are by beheading with a sword.
In a press conference Saturday, Interior Ministry spokesman Maj. Gen. Mansour al-Turki said the executions were carried out inside prisons and not in public. He described the executions as an example of Saudi Arabia's tough response to terrorism.
In announcing the verdicts, Saudi state television showed mugshots of those executed. Al-Nimr was No. 46, expressionless with a gray beard, his head covered with the red-and-white scarf traditionally worn by men in the Arab Gulf region.
Al-Nimr, who was in his 50s, had been a vocal critic of Bahrain's monarchy, which forcibly suppressed protests in 2011 with the help of Saudi troops. He was popular among disgruntled Shiite youth in both Bahrain and Saudi Arabia.
U.S.-based Human Rights Watch's Middle East director Sarah Leah said "regardless of the crimes allegedly committed, executing prisoners in mass only further stains Saudi Arabia's troubling human rights record." She said al-Nimr was convicted in an "unfair" trial and that his execution "is only adding to the existing sectarian discord and unrest."
Al-Nimr never denied the political charges against him, but maintained he never carried weapons or called for violence.
At his trial, he was asked if he disapproved of the Al Saud ruling family after speeches in which he spoke out forcefully against former Interior Minister and late Crown Prince Nayef bin Abdelaziz.
"If injustice stops against Shiites in the east, then (at that point) I can have a different opinion," the cleric responded, according to his brother Mohammed al-Nimr, who attended court sessions and spoke to The Associated Press before the verdict.
Al-Nimr's brother told the AP by telephone that the executions came as a "big shock" because "we thought the authorities could adopt a political approach to settle matters without bloodshed." He urged people to "adopt peaceful means when expressing their anger."
Mohammed's son Ali, the cleric's nephew, is also facing execution, but his name was not among those listed Saturday. Amnesty International describes Ali al-Nimr as a juvenile offender because he was 17 years old in February 2012 when he was arrested. He was later convicted, and his death sentenced upheld, on charges of attacking security forces, taking part in protests, armed robbery and possessing a machine-gun.
After listing the names and images of those executed, Saudi state television showed black-and-white footage of previous terror attacks in the kingdom, one showing bodies in a mosque after an attack. Soft, traditional music played in the background.
Saudi Arabia carried out at least 157 executions in 2015, with beheadings reaching their highest level in the kingdom in two decades, according to several advocacy groups that monitor the death penalty worldwide.
Batrawy reported from Dubai, United Arab Emirates. Associated Press writers Jon Gambrell in Dubai, Maamoun Youssef in Cairo, Reem Khalifa in Manama, Bahrain, Ali Akbar Dareini in Tehran, Iran, Sinan Salaheddin in Baghdad and Bassem Mroue in Beirut contributed to this report.