Dubai (Agencies): Reminding recent upheaval at Tahrir Square in Egypt, the anti-government demonstrators continue to throng a prominent square in Bahrain's capital on Wednesday, despite an atypical apology by the King for deaths of two demonstrators in police firing in the last two days.

The protesters, wanting political reforms and better human rights in the kingdom, are refusing to leave the square in Manama, after two days of violent clashes and an assurance by the Monarch "to investigate the killings", local media reports said.

King Sheikh Hamad bin Isa Al-Khalifa made a rare TV appearance on Tuesday in which he expressed his condolences for "the deaths of two of our dear sons" and said that a panel would probe into the deaths of the demonstrators.

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

The protesters in thousands have been demonstrating since Monday. One person was killed on Tuesday in police firing eliciting anger among cyber activists who had called for the Manama demonstration on Facebook.

MPs from Bahrain's main Shiite opposition bloc also walked out of Parliament.

Bahrain was hit by deadly unrest in the 1990s between the majority Shiite population and the Sunni ruling family.

US expresses concern

Expressing its concern on the violence in protests in Bahrain, the United States has urged all sides to exercise restraint.

"The United States is very concerned by recent violence surrounding protests in Bahrain. We also call on all parties to exercise restraint and refrain from violence," stated PJ Crowley, the US State Department spokesman.

He lauded the Bahraini government’s promises to probe into the deaths of two protesters and to "take legal action against any unjustified use of force by Bahraini security forces.

Bahrain, a small island kingdom in the Gulf, has little oil resource but it is home to a thriving regional banking and financial-services sector and hosts the US Fifth Fleet, the naval command in charge of Persian Gulf.