A man lost several fingers early Saturday when illegal fireworks he and three friends were setting off from a car while driving along San Francisco’s Mission Street exploded prematurely.

Authorities said the four men were firing off professional grade fireworks around 2:20 a.m. when one blew up in the man’s hand as he held it out of the window.

The force of the explosion left one of the injured man’s fingers impaled on a fence at 4175 Mission and another lying in the gutter. He was taken to a local hospital for emergency treatment.

In Oakland last night, firefighters blamed illegal fireworks use for a blaze that engulfed a home under construction.

The San Francisco bomb squad officers also picked up illegal fireworks at 22nd and Treat and on Third St. near AT&T Park among other locations during the night. In all, about 1,000 pounds of illegal fireworks were seized by SF police overnight and will be held until CalFire can safely dispose of them.