(CNN) -- Police used excessive force and torture against civilians arrested during a crackdown on protests earlier this year, an independent commission set up by Bahrain's king, Hamad al-Khalifa, found Wednesday.
Abuses of detainees included beatings with metal pipes and batons, threats of rape and electrocution, commission chairman Prof. Mahmoud Cherif Bassiouni said.
The mistreatment included physical and psychological torture, he said, intended to extract information or to punish those held by security forces.
Bahrain should set up an independent body to investigate complaints of killings and torture during the pro-democracy protests in the capital, Manama, earlier this year, Bassiouni said, and all those involved in human rights abuses should be held accountable, no matter how high their position.
The highly critical report by the Bahrain Independent Commission of Inquiry recommended a series of reforms to the country's law and better training of its security forces, which have not yet been held accountable for abuses.
Protesters should no longer be tried by special military courts outside the normal legal system, Bassiouni said, and compensation should be paid out to those mistreated and the families of those killed.
Speaking after the report was given, the king vowed that mistreatment of detainees would no longer be tolerated.
This day "turns a new page of history" for Bahrain and the kingdom would seek to meet international standards on human rights in the future, he said.
"We are determined, God willing, to ensure that the painful events our beloved nation has just experienced are not repeated, but that we learn from them, and use our new insights as a catalyst for positive change," he said.
Any government should be able to take on board constructive criticism and carry out reforms for the benefit of its people, he added, rather than boycotting those who made the criticisms.
Protests demanding political reform and greater freedoms in Sunni-ruled, Shiite-majority Bahrain began February 14 before authorities -- backed by troops from Saudi Arabia and the United Arab Emirates -- cracked down on the demonstrations, first in February and later in mid-March.
Thirty civilians and five security officers were killed during the protests, the commission said.
British Foreign Secretary William Hague welcomed the report but described its findings as "deeply worrying, in particular the use of systematic torture and excessive force against detainees."
He urged Bahrain's government to act swiftly to implement its recommendations and said the world would be watching "to ensure that it acts decisively in the coming days and weeks to address the serious abuses identified."
The United States-based Physicians for Human Rights called on the Bahraini government to make "substantive and irreversible human rights improvements" in the wake of the commission's findings.
Deputy director Richard Sollom said: "So far, the government appears to be saying the right things, but words are not enough. To demonstrate a real commitment to reform, the government must now make meaningful and measurable changes."
Opposition groups say more than 1,000 people -- mainly Shiites -- have been detained for allegedly taking part in the demonstrations. A number of medical personnel have been convicted of trying to overthrow the government.
Thousands of private and public sector workers were also sacked for allegedly taking part in the demonstrations and many students were barred from continuing their studies, Bassiouni said.
The commission also found evidence of sectarian harassment of Sunnis during the crackdown on protests, he added.
This "collective punishment" included the destruction of 30 religious sites, he said, and led to heightened tensions between the government and people.
Foreigners working in Bahrain, including workers from South Asia, were also subjected to racist abuse and attacks, the commission found.
The king accused Iran, another Shiite-majority nation, of fomenting insurrection in his country, saying "round-the-clock" broadcasts from Iranian state media had "fueled the flames of sectarian strife -- an intolerable interference in our internal affairs from which Bahrain has suffered greatly."
The government admitted Monday to the use of "excessive force" against opposition protesters, ahead of the report's release, saying it had begun legal action against 20 police officers accused of mistreatment.
That statement represented a reversal in the stance of the government, which had previously defended its actions, saying they were justified and needed to maintain public security in the tiny but strategically critical nation that is home to the U.S. Navy's Fifth Fleet.
The nation's king set up the commission to investigate the events -- and consequences -- of the unrest earlier this year.
"All the while BICI has carried out its work, the government has carried out its own assessments and conducted its own investigations. These investigations have revealed things to praise as well as things to deplore," the government statement Monday said. "Regrettably, there have been instances of excessive force and mistreatment of detainees. This was in violation of government policy."
Amnesty International has called on Bahrain to take action on the commission's inquiry.
"Allowing this independent inquiry into the Manama protests and their aftermath was a very welcome move, but the whole exercise will have been meaningless if the report's recommendations are not translated into real action to redress abuses," the human rights group said.
CNN's Laura Smith-Spark contributed to this report.