A teenager has been killed during a protest in Bahrain marking the second anniversary of the country's pro-democracy rallies, activists have said.

Hussain al-Jaziri, 16, was reportedly killed by shotgun fire during a protest in Al-Daih, a village west of the capital Manama. Witnesses said that he was shot at close range.

On Friday, Bahrain's interior ministry said that a police officer had died after being hit by an incendiary device thrown during clashes with protesters a day earlier.

Earlier, the ministry had confirmed on Twitter that a person had died, but offered no further details.

"[The] operations room received [a] call from SMC reporting an injured individual pronounced dead. Public prosecutor was informed," the tweet said, referring to Salmaniya Medical Complex, the largest hospital in Bahrain. It was unclear if the statement referred to the police officer or the teenager.

The ministry also said that "rioters" had blocked roads.

Hundreds of people had protested on Thursday in villages across the country, and there were reports of tear gas being used in several locations. Three Bahraini photojournalists were arrested while working in Daih, according to one of them, Mazen Mahdi, who tweeted about his arrest.

New 'national dialogue'

Protesters set up camp at Pearl Roundabout in Manama two years ago, and remained there for nearly a month before being forcibly expelled in mid-March. Authorities later razed the iconic statue at the centre of the square.

More than 80 people have been killed during the two years of unrest.

The government set up an independent commission to study the events. Its report, released in late 2011, documented the excessive use of force against mostly peaceful protesters.

Bahrain says it has implemented the report's recommendations, but the opposition says that abuses continue, with regular reports of torture and the widespread use of tear gas in villages.

A new round of "national dialogue," organised by the government, began on Sunday.

The talks includes representatives from Al Wefaq and other opposition groups, plus members of pro-government groups like the National Unity Gathering and Asala, a Salafi party.

Officials have revealed little about the substance of the talks so far.

The opposition has continued to press for major political reforms, including a constitutional monarchy and an elected prime minister.