On the first anniversary of the start of protests in Bahrain Tuesday, crowds and police clashed in the Gulf island nation's capital.

On Monday and Tuesday, the monarchy's police and army did their best to stop the types of demonstrations that led to dozens of deaths between Feb. 14 and 17 of last year, but were unable to keep the peace in isolated sections of Manama.

Troops were sent to various rally points across Manama, including Shi'ite neighborhoods and the Pearl Roundabout, which was the site of a Tahrir Square-like sit-in at the start of the uprising. The monument there has been torn down and police arrested at least 30 people trying to gather at the landmark on Tuesday.

But the Pearl Roundabout became a flashpoint for skirmishes between police and protesters nonetheless. Police fired teargas and rubber bullets into the crowds, while youths responded with rocks and Molotov cocktails.

They fired straight at us; they weren't even shooting in the air, one of the protesters told Reuters.

Similar reports have been common since the unrest started in Bahrain last year. Upwards of 70 people have been killed since last February, many of them reportedly shot at close range by police with shotguns and tear-gas canisters, sometimes in the back and head.

Six Americans were also arrested for violating the terms of their visas. The Americans -- member of Witness Bahrain, a civilian monitoring group -- will be deported, the Bahraini government reportedly said.

The six U.S. citizens were part of a peaceful protest marching towards the Pearl Roundabout... when they were attacked, Witness Bahrain stated. Bahraini authorities appear to have targeted the Witness Bahrain observers, as one volunteer was told that she was detained for reporting on the February 11th Manama protest.