A car which was being pursued by gardai was involved in the serious crash at Johnstown this afternoon, RTE has reported.
The vehicle reportedly crashed into a third car. One man has been seriously injured.
A number of men who were in the pursued car are currently being sought by gardai. Investigators are currently at the scene.
The incident has caused huge tailbacks on the N7 inbound to Dublin this evening. Diversions are currently in place via the slip road at Johnstown, but the delays are stretching back past the M7/M9 junction.
UPDATE: 5.45PM: A second crash has been reported on the N7 Dublin/Limerick road southbound at J8 Johnstown. Delays on approach are building.