"I don't yet understand why I got such a poor start - it lost me ground and then I fell under attack from the guys behind," Sky Sports News quotes Hamilton as saying.
"During the first lap, I was primarily focusing on not colliding with Jenson, then I saw Fernando [Alonso] in my right mirror. He was towing me from very far back.
"Even if I'd had a better start than I did, the guys in front were still maybe a bit too fast, particularly in the first stint."
Hamilton is fifth in the drivers' championship.