An independent report on human rights in Bahrain on Wednesday painted a grim picture of systematic abuses of pro-democracy protesters this year.
The report by Cherif Bassiouni, a human rights lawyer, criticized a culture of impunity for security officials.
But it did not name high-level officials nor accuse the regime of crimes against humanity.
He vowed to implement reforms in an attempt to forge reconciliation in a country torn apart by the conflict between a minority Sunni regime and a majority Shia population.
“You found real shortcomings from some government institutions,” said the king. “Officials who have not been up to their task must be held accountable and be replaced.”
The king, however, stuck to the story that he and his Gulf partners, who rushed troops to Bahrain this year to prop up the royal family, believed that Iran had incited the protests.
He said the Islamic Republic had “fueled the flames of sectarian strife,” and this amounted to “an intolerable interference in our internal affairs.”
The 500-page report by Mr Bassiouni’s commission detailed abuses by Bahrain’s national intelligence agency and interior ministry against protesters during and after demonstrations in February and March.
In many cases, these amounted to torture, including examples of beatings, electrocution and threats of rape.
Five of the 45 deaths that took place during the commission’s period of investigation, from February 14 until April 15, came as the result of torture, it said.
But the report stopped short of accusing the Bahraini leadership of ordering any killings.
Mr Bassiouni recommended that an impartial mechanism should be created to bring to account government officials for their roles in deaths and torture.
He also urged the government to review all judgments against civilians brought by military courts set up after a crackdown on protests that followed the Saudi-led deployment of Gulf troops to aid the government in March.
While most claims in the report had previously been reported, the clarity of the assessment will raise pressure on the government, which said it would set up its own panel to examine the commission’s recommendations, to implement real change or face rising international pressure.
The king faces pressure to tackle hardline elements within the ruling family that are believed to have led the crackdown in mid-March after six weeks of protests on the Pearl roundabout.
Some activists said the report did not go far enough in apportioning blame for the abuses and questioned the willingness of the government to implement recommendations from the Bahrain Independent Commission of Inquiry (BICI).
Winning support from the minority Sunni community and Gulf neighbours for any reform effort could prove to be the greatest challenge for the king and his more reformist crown prince, Sheikh Salman bin Hamad Al Khalifa.
The report also noted that two expatriates and three security officers died as the result of attacks from demonstrators.
It said members of the minority Sunni community were subject to attacks and harassment.
The BICI report said systematic abuse of detainees had ended in June, when a state of effective martial law was lifted, but noted that abuses were continuing against those arrested for taking part in demonstrations since July.
Before the report’s publication, renewed clashes broke out in the village of Aali after a man died in a car crash.
Police used teargas to quell protests said witnesses.