The incident took place at 11:09 local time (18:09 GMT). The shooter was suspected to be on a rooftop of a parking, according to the broadcaster.
The police has arrived at the scene, the media outlet reported. Later, NBC broadcaster reported that the police arrested the shooter, citing a source close to the investigation.
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In an hour after the incident, the marathon resumed. There was no additional information on possible injuries or damage available at that moment.