Friday's practice sessions for the Bahrain Grand Prix were overshadowed by the continued anti-government protests and safety concerns in the Gulf State.

The Force India team elected not to take part in the day's second practice after four mechanics for the British-based outfit were caught up in a clash between police and protestors on Wednesday and only narrowly avoided being hit by petrol bombs.

The incident happened as the mechanics made the journey from the track back to their hotel in the capital, Manama, at night. As a result Force India did not want to take the chance of making the same journey after dusk.

We shouldn't have been put in this position, said Force India driver Nico Hulkenberg, according to the Telegraph. It is obviously not right that that sort of stuff happens.

A similar incident happened to the Sauber team, when a bus carrying 12 mechanics encountered a burning bottle and masked men running toward their vehicle.

No-one was hurt in the incident and Sauber do not believe they were the targets of an attack, according to the BBC.

On the track itself, Nico Rosberg continued his fine form, after taking pole and the checkered flag in China, by finishing top of the time sheets in P2. The Mercedes driver finished 0.446secs ahead of Mark Webber in the Red Bull, with the Australian's team mate a further place back.

Lewis Hamilton, who was almost a second slower than Rosberg in P2, had been the quickest in the day's first practice session.