Caleb Amisi Luyai an opposition politician of the National Super Alliance (NASA) coalition, reacts after a gas canister fired by policemen hits his car during a protest along a street in Nairobi, Kenya, October 13, 2017. Reuters photographer

NAIROBI (Reuters) - In a dramatic picture, Kenyan opposition lawmaker Caleb Amisi Luyai leans through the window of his car as tear gas billows out, police having fired it at a convoy of opposition politicians in Nairobi on Oct. 13.

Police acted to prevent the politicians from entering the center of the capital to enforce a ban on staging political protests there ahead of a repeat presidential election.

Kenya is holding a re-vote on Oct. 26 after the Supreme Court threw out the result of an election in August won by incumbent President Uhuru Kenyatta.

His opponent, Raila Odinga, is boycotting the repeat, arguing that it should not be held until wide-ranging reforms are adopted to prevent another failed vote.

For Reuters photographer Baz Ratner, who took the image, “the main challenge is how to cover the story when the protests are moving very fast in a few different focal points around Nairobi”.

Ratner had ridden just ahead of the opposition convoy on his motorcycle when tear gas canisters were fired.

“I stopped on the side of the road and put on my gas mask when I noticed one of the cars was engulfed in smoke. It was moving forward slowly, while I ran towards it as I took a few photos.”

Ratner did not recognize the driver, Luyai, an opposition member of parliament, but saw him leaning out of the window and gesturing.

“I helped him open the door. I walked to the other side where other people who were in the car were lying on the floor. Very quickly, the car drove away,” Ratner said.