A minute's silence will be held before Sunday's British Formula One Grand Prix in memory of the victims of the explosions in London [Images].

"The FIA, Formula One Management, Silverstone Circuits, the teams, drivers and everyone involved in Formula One send their condolences and deepest sympathies to the families and friends of those who lost their lives," the sport's governing International Automobile Federation (FIA) said in a statement.

Security has been stepped up at Silverstone after Thursday's blasts, with cars and bags searched at entrance points.

The event is sold out, with 100,000 people expected on Sunday.

Organisers said on Thursday they were confident adequate security measures were in place.

Four blasts hit packed London underground trains and a double-decker bus at rush hour early on Thursday, killing more than 50 people.

"I think I speak on behalf of everyone involved in Formula One, that we are obviously deeply shocked and saddened by what has happened in London," said BAR's Jenson Button [Images], the only English Formula One driver.

"My heart goes out to all the victims and the victims' families that have been involved.

"It is obviously a difficult way to start the weekend for everyone, but we are going to try to put the best show on we can for the fans in the situation we have."

• Formula One coverage