Bahrain, United Arab Emirates - Mercedes' Nico Rosberg was quickest during the second practice session with a time of 1min32.816 ahead of the 2012 Bahrain f1 GP. Rosberg led the Red Bull duo of Mark Webber (1min33.262) and Sebastian Vettel (1min33.525). McLaren's Lewis Hamilton, fastest during the first sesson, was fourth with 1min33.747.Force India chose not to take part in the second session and instead focus on qualfiying. The teams used their allocation of soft tyres during the first session. Four of the team's mechanics were close to a confrontation between police and protesters on the highway back to the capital city Manama when a petrol bomb ignited close to their unbranded rental car.Sauber issued a statement that confirmed they drove through a similar incident. None of the 12 mechanics in the unmarked mini-bus was hurt.Seven-times champion Michael Schumacher was fifth in the second Mercedes ahead of Hamilton's McLaren team mate Jenson Button, Sauber's Kamui Kobayash and Ferrari's Fernando Alonso.Romain Grosjean was ninth for Lotus and Sauber's Sergio Perez wound up 10th.Bahrain Grand Prix: Second free practice times1 Nico Rosberg (Germany) Mercedes 1min32.816 2 Mark Webber (Australia) RedBull 1min33.262 3 Sebastian Vettel (Germany) RedBull 1min33.525 4 Lewis Hamilton (Britain) McLaren 1min33.747 5 Michael Schumacher (Germany) Mercedes 1min33.862 6 Jenson Button (Britain) McLaren 1min34.246 7 Kamui Kobayashi (Japan) Sauber 1min34.411 8 Fernando Alonso (Spain) Ferrari 1min34.449 9 Romain Grosjean (France) Lotus 1min34.615 10 Sergio Perez (Mexico) Sauber 1min34.893 11 Dzniel Ricciardo (Australia) Toro Rosso 1min34.895 12 Felipe Massa (Brazil) Ferrari 1min34.941 13 Kimi Raikkonen (Finland) Lotus 1min35.183 14 Jean-Eric Vergne (France) Toro Rosso 1min35.229 15 Pastor Maldonado (Venezuela) Williams 1min35.459 16 Vitaly Petrov (Russia) Caterham 1min35.913 17 Heikki Kovalainen (Finland) Caterham 1min35.968 18 Bruno Senna (Brazil) Williams 1min36.169 19 Timo Glock (Germany) Marussia 1min36.587 20 Charles Pic (France) Marussia 1min37.803 21 Pedro de la Rosa (Spain) HRT 1min37.812 22 Narain Karthikeyan (India) HRT 1min39.649 23 Paul Di Resta (Britain) Force India N/A 24 Nico Huelkenberg (Germany) Force India N/AFirst free practice times Stay with Wheels24 for the Bahrain F1 Grand Prix weekend.