BBC executives have admitted making major errors in its coverage of Bahrain's unrest.

The organisation initially underplayed the sectarian aspect of the conflict and did not adequately convey the viewpoint of supporters of the monarchy, says a BBC Trust report.

It also failed to mention attempts by Crown Prince His Royal Highness Prince Salman bin Hamad Al Khalifa to establish dialogue with the opposition, according to the publication - which investigated the organisation's "impartiality and accuracy" of its coverage of the Arab Spring.

"They seemed rather to anticipate criticism from the opposite quarter and volunteered acknowledgement of a degree of partiality, during the first weeks of the disturbances, in favour of the opposition," said BBC security correspondent Frank Gardner in the 89-page report, nine of which were dedicated to the BBC's coverage of events in Bahrain.

Head of newsgathering Fran Unsworth said the BBC initially struggled to get the complexities across of the unrest, a view backed up by World News Editor Jon Williams.

"In Bahrain at the beginning we viewed this through the prism of what was going on elsewhere - a default narrative about a Shia majority oppressed by a Sunni minority, but it is more complex than that," he said in the report.

Director of Global News Peter Horrocks also spoke out about the BBC's coverage of the unrest.

"In Bahrain it's important to understand the Sunni perspective on the insurgent threat ... not to excuse, but to explain why the regime was responding the way it was," he said.

In assessing its coverage during the first weeks of last year's disturbances, the report said it was hardly surprising that protests in Bahrain were presented in the context of the Arab Spring - given they happened only three days after the fall of former Egyptian president Hosni Mubarak.

Criticised

But a two-minute news item by BBC Middle East correspondent Ian Pannell was heavily criticised.

"This report, put together in 24 hours or less in very difficult conditions, conveyed a lot of information in two short minutes, while effectively engaging viewers in the human drama of a small, faraway country of which most of them probably knew nothing.

"On one level, therefore, a good example of BBC professionalism, but there was a crucial omission: no mention of sectarian divisions in the country or its previous history of conflict.

"Obviously reporters cannot be expected to rehearse the entire history of a conflict each time they report on it, but this was probably the first time some viewers would have heard anything at all about Bahrain and only a handful are likely to have been aware of its demographic and political problems.

"Here was an incomplete account, which showed no awareness of Bahrain's specific history and context, but saw the conflict there through the prism of revolts elsewhere in the region."

The report said the mistakes left many people feeling the BBC's coverage was "utterly one-sided".

"The Bahrain government was far from reacting in the single-mindedly ruthless manner adopted in the same days and weeks by Gadaffi in Libya and later by Assad in Syria," said the report.

"In particular, between 19 February and 14 March (last year) the government appears to have made a good-faith effort to de-escalate the crisis."

The report referred to the setting up of the Bahrain Independent Commission of Inquiry, the Crown Prince's attempts to reach a solution to the crisis, the dismissing of four Cabinet Ministers, pardoning people convicted in political cases and allowing exiled political leaders to return.

"The government of Bahrain also allowed demonstrations and marches to be held throughout Bahrain and ensured that the public security forces exercised considerable self-restraint and did not disperse these protests," it said.

"No fatalities were recorded during the period from 18 February to 15 March 2011."

Referring to the breakdown of negotiations between the Crown Prince and opposition, sectarian clashes at Bahrain University, protests by schoolchildren, attacks against expatriates, the blocking of major roads by protesters and setting up of illegal checkpoints, the report said it was not surprising Bahrain brought in outside help.

"All these developments no doubt contributed to the government's decision to call for assistance from its partners in the Gulf Co-operation Council, to declare a state of emergency and to resort to a much more thorough crackdown on the opposition, in the course of which many further killings and other human rights violations occurred," said the report.

"It was therefore unfortunate that the period between 18 February and 15 March also coincided with a sharp drop in the BBC's attention to the crisis and the departure of its correspondents," said the report.

"The BBC's audience, especially its domestic television audience, was thus treated to two brief bursts of coverage at moments when the government was cracking down, but was told virtually nothing about what happened in the crucial three-week period in between.

"It was this, rather than any actual misrepresentations or inaccuracies, which made its coverage appear to some "utterly one-sided."

The BBC's two-part documentary series Riots and Revolutions, presented by 24-year-old Afghanistan presenter Nel Hedayat, was also criticised.

"Bahrain was one of the chosen four, but not the best handled," said the report.

"Hedayat's host there was a doctor who had been imprisoned and (she claimed) tortured during the crackdown, but was now out on bail.

"The doctor's statements about the political situation were all accepted uncritically and although the programme noted that the government said it was acting in self-defence and had urged protesters to exercise self-restraint."