Manama, Feb 16 (IANS) The king of Bahrain, Sheikh Hamad bin Isa Al-Khalifa, made an appearance on state television in which he condoled the death of two protesters, as the country's main Shia opposition group announced it was withdrawing from parliament.

Hamad expressed his condolences for "the deaths of two of our dear sons" in a televised speech and said a committee would investigate the killings, Al Jazeera reported.

"We will ask legislators to look into this issue and suggest needed laws to resolve it," he said, adding that peaceful protests were legal in the country.

At least one protester was shot dead and several injured Tuesday after police opened fire at crowds who had gathered in the Bahrain capital for the funeral of a man who had died after being grievously wounded in bloody clashes a day earlier.

Fadhel Ali Almatrook was shot by riot police Tuesday morning while he was walking along with other protesters from the hospital to the cemetery, said Maryam Alkhawaja, head of foreign relations at the Bahrain Centre for Human Rights.

Al-Wefaq, Bahrain's main Shia Muslim opposition group, announced it was suspending its participation in the parliament.

"This is the first step. We want to see dialogue. In the coming days, we are either going to resign from the council or continue," said Ibrahim Mattar, an al-Wefaq MP.

Alkhawaja said thousands of people were marching on the streets, demanding the removal of the regime, when police fired tear gas shells and bird-shot, and used "excessive force" - "that is why people got hurt".

The US, meanwhile, said it was "very concerned" by recent violence in protests in Bahrain, and urged all sides to exercise restraint.

"The US is very concerned by recent violence surrounding protests in Bahrain," State Department spokesman P.J. Crowley said. "We also call on all parties to exercise restraint and refrain from violence."

At least 25 people were treated for injuries in hospital.

The crowds chanted "The people demand the fall of the regime!" as they poured into Manama's Pearl Roundabout after marching from the funeral on the city's outskirts.

Al Jazeera reported that police took a "very heavy-handed approach" towards the protesters.

The funeral procession was allowed to continue, but police were "playing a cat-and-mouse game" with the protesters, it said.

The protesters said their main demand was the resignation of Prime Minister Sheikh Khalifa bin Salman al-Khalifa, who has governed Bahrain since its independence in 1971.

The protesters were also demanding the release of political prisoners, which the government had promised earlier, and the creation of a new constitution.