A leak of 100 gallons of an unknown liquid substance caused several multivehicle crashes on I-95 in New Rochelle this morning.

The spill from an unknown tractor-trailer caused extremely slippery conditions around 6:45 a.m.

In all, 21 passengers and two tractor-trailers were involved in the crash that occurred over a span of a mile near Exit 16 northbound.

Seven people were taken to Montefiore-New Rochelle Hospital for minor injuries.

All lanes were reopened shortly after 9 a.m.