Sergio Perez has said that his crash in first practice at the Hungarian Grand Prix was a "strange accident".
The Force India driver flipped the car upside-down after losing control at the Hungaroring and colliding with a barrier.
The Mexican, who walked away unscathed, told Sky Sports News: "It was just a bad accident, really unlucky. The track was very dirty. I was on the astroturf and on the wrong side of the track, a very bad angle so it made the car roll over. But everything's all right.
"It was a bit of a strange accident. I thought it was all under control but I guess the astroturf was very dirty and that's why I went into the wall. But we have to check everything in detail."
Force India kept Perez and teammate Nico Hulkenberg out of second practice while they investigated the cause of the accident.
