A volley of automatic gunfire hit a car carrying a senior aide to Ukrainian President Volodymyr Zelenskiy on Wednesday, an incident a senior official called an assassination attempt and Zelenskiy said may have been a message intended for him.

The aide, Serhiy Shefir, survived unscathed but police said his driver had been wounded in the attack near the village of Lesnyky, just outside the capital Kyiv.

A prosecutor said the car had been hit 18 times, and multiple bullet holes could be seen along the driver’s side.

Police said in a statement they had opened a criminal case on suspicion of premeditated murder.

Zelenskiy, who is in New York for the UN General Assembly, said he did not know for now who was responsible for the attack, which shocked the country’s political elite.

“I don’t know yet who stood behind this,” said Zelenskiy. “Sending me a message by shooting my friend is weakness.” Shefir is close to Zelenskiy and leads a group of advisers. “I have not conducted any cases that would have caused aggression. I think this is intimidation,” Shefir told a joint news briefing with police and interior minister Denys Monastyrsky.

“I think this won’t frighten the President,” he added.

Zelenskiy came to power on a promise to take on the country’s oligarchs and fight corruption.