WALNUT CREEK -- A collision between an ice cream truck and a red taxicab snarled traffic on northbound Interstate 680 at Rutgear Road early Friday morning, the California Highway Patrol said.

The collision was reported about 7:15 a.m., when the taxicab collided with the ice cream truck, flipping the truck on its side and causing it to leak gasoline, a dispatcher said.

No injuries were reported in the collision, the dispatcher said, but several lanes were blocked.

A second crash ensued in the resulting backup, causing further delays all the way up to San Ramon, the CHP said.

Three lanes of the freeway were blocked until about 9 a.m. while officials investigated the crashes.

Contact Erin Ivie at 925-847-2122. Follow her at Twitter.com/erin_ivie.