Bahrain's crown prince has made a renewed appeal for dialogue to end the political impasse in the Gulf kingdom, a call welcomed by the Shia-led opposition.

Prince Salman Bin Hamad Al-Khalifa, widely viewed as a moderate member of the Sunni ruling dynasty, took the opportunity when hosting a global security conference last week to invite the Shia opposition to sit down and talk.

"We had our own experience of the so-called Arab Spring last year. It divided the nation, and many wounds are still to be healed," he told the conference.

"I am convinced ... that dialogue is the only way forward."

Bahrain is a small but strategic nation across the Gulf from Iran, and is base to the US Fifth Fleet.

Prince Salman added: "Opposition leaders must condemn violence on the streets. Silence is not an option," while insisting that "political groups must be reconciled."

State Minister for Information Samira Rajab reiterated the same line, telling AFP that "dialogue is the only solution; a consensual dialogue between all forces to reach a comprehensive solution."

Al-Wefaq, the largest Shia opposition formation, seized on the crown prince's proposal and responded positively, but demanded a "serious dialogue" and said the results must be subject to a referendum.

The crown prince's latest overture is just one in a series of calls he has made since February 2011.

It was then that activists, mostly from Bahrain's Shia majority, took to the streets to demand democratic reforms, but were crushed by forces loyal to the Sunni monarch with the aid of Gulf troops led by Sunni neighbour Saudi Arabia.

The opposition has repeatedly said it is ready for a meaningful dialogue, but has stuck to its demands for a genuine constitutional monarchy with an elected prime minister.

Khalil Al-Marzooq, a former Al-Wefaq MP, said the group was ready to talk.

"We are ready for dialogue without any conditions," he said, reiterating his movement's position, which does not challenge the monarchy but demands that "the prime minister be named by the elected parliament."

Current Prime Minister Prince Khalifa Bin Salman, an uncle of the king, has been in office since 1971, and is widely despised by Shias.

Calls for his ouster echo in almost every demonstration organised by Al-Wefaq or any other Shia opposition group.

But on the walls in Shia villages outside Manama, graffiti calls for more: the departure of King Hamad.

In those villages black flags of mourning fly and portraits of the revered 7th century Imam Hussein are displayed next to posters of radical Shia opposition figures jailed following last year's crackdown on dissent.

Despite a brutal clampdown in which a protest camp at Manama's Pearl Square was demolished and protesters were chased back to their villages, it was not long before demonstrators were back on the streets.

According to the International Federation for Human Rights, a total of 80 people have been killed in Bahrain since the violence began 14 February 2011.

Confrontations between mostly youthful protesters and police occur frequently after calls made on social media networks by the "February 14 Movement," which was behind last year's protests.

The demonstrations in Shia villages often turn violent with the police firing tear gas and birdshot and protesters responding with Molotov cocktails.

Key ally Washington urged the Bahraini authorities in November to exercise self-restraint.

Some observers have questioned whether traditional opposition groups, mainly Al-Wefaq, are in control of the protests, as radical groups appear active.

"We have not lost control of the street," insisted Marzooq, but adding that protesters' demands have become "stern," and acknowledging that "violence has increased."

Manama came under strong criticism from international rights groups over last year's deadly crackdown.

An international panel commissioned by King Hamad found that excessive force and torture was used against protesters and detainees.

The government has made no concessions to the opposition since, but claims to have begun a robust implementation of the special commission's recommendations.

"Almost all those sacked" for taking part in protests, estimated at around 4,400 people, "have been reinstated in their jobs," and police have adopted a "new code of conduct," Rajab said.