Formula One teams are expected to enhance their own security ahead of the confirmed visit to Bahrain next week.

The FIA yesterday finally broke their silence on the thorny issue of the April 22 race in the troubled Gulf kingdom by announcing the event will go ahead as scheduled. Crucially, it remains to be seen what response there will be in Bahrain from the anti-government demonstrators who have long campaigned against the grand prix going ahead.

Even last night an explosion rocked the capital of Manama and although no-one was injured – two cars were damaged – it is the first serious incident to occur of late at the heart of the country.

Regardless, an FIA statement confirmed its satisfaction that "all the proper security measures are in place for the running of a Formula One World Championship event in Bahrain".

Despite that, the teams will take their own precautions, as is always the case when F1 visits Brazil where the prospect of a car-jacking is high.

Mark Webber yesterday confirmed security would be high within Red Bull as he said: "There are measures in place, yes. There is added security."

Webber, the most outspoken of all drivers yesterday, appreciates that while the show must go on, there are niggling concerns. "If we had a choice would we go? I want to race. That is what I would like to go there and do," said Webber.

"But saying that you cannot ignore the fact that all of us, in the backs of our minds, want it to go down smoothly and don't want it to be involved in the unrest.

"We want the people out there to support our race. That is why it is so sensitive."

The only other driver to offer his considered thoughts was Jenson Button, who called for the sport to portray a unified front.

"We have to stay united as F1 because to say teams can make their own decisions is wrong," said Button.

"We're racing in the championship, so if one team doesn't go it is 25 points lost, which is massive.

Meanwhile, Button's team-mate Lewis Hamilton left it until the last possible moment to post the quickest lap in first practice for Sunday's Chinese Grand Prix.

Overnight rain forced a slow start before the majority of the drivers made their way out on to the circuit, initially on the intermediate tyres to cope with the conditions.

However, both Hamilton and Button saved a set of inters by not venturing out early, which could prove valuable given the weather is forecast as changeable.

It was not until the closing stages that Hamilton took advantage of a dry line around the Shanghai International Circuit, and on a medium set of dry tyres.

With his first quick lap the 27-year-old deposed Webber from the top of the timesheet, and although Nico Rosberg briefly took over, Hamilton then blitzed it with his subsequent fast lap.

In posting a time of one minute 37.106seconds, Hamilton finished 1.010secs quicker than Rosberg, albeit 3.4secs slower than Sebastian Vettel's pole lap of last year.

Rosberg's team-mate, seven-time champion Michael Schumacher, was 0.2secs down on his fellow German, with the duo followed by the Saubers of Sergio Perez and Kamui Kobayashi.

Webber ultimately finished 1.871secs adrift of Hamilton, who this weekend faces a five-place grid penalty for a gearbox change.

The remainder of the field, spearheaded by reigning world champion Vettel in seventh, were all at least two seconds down. That included Button who was only a thousandth of a second behind Vettel, but 2.093secs off of Hamilton, with the Toro Rosso pair of Daniel Ricciardo and Jean-Eric Vergne completing the top 10, but with both 2.6secs off the pace.