A man in his 20s was fatally shot by a police officer in Santa Clara on Thursday, according to the Santa Clara Police Department.

About 5 p.m., police responded to a call to Deborah Drive, near the intersection of Monroe Street and Scott Boulevard, on reports of a man acting "erratically." The call came from one of the man's parents, police said.

Soon after officers arrived and encountered the man, the situation escalated to the point where an officer deployed his Taser, police said. Moments later, the situation "transitioned," and the officer shot the man on railroad tracks adjacent to the end of Deborah Drive, police said.

Police did not say whether the man was armed or how the situation transitioned but emphasized that a nonlethal option had been used first.

"At this point, it’s too early to speculate," Capt. Wahid Kazem said about the shooting. "He’s some distance, so there was some movement. But how that happened is not clear to me right now."

The man was not identified by police. The officer, who has been on the Santa Clara force for eight years, will be placed on administrative leave, police said.

The investigation closed the southbound lanes of Scott Boulevard between Monroe and Martin Avenue for hours, and police asked the public to avoid the area.

No officers were injured, police said.

All Santa Clara officers wear body cameras, but Kazem had not yet determined if the officer involved in the shooting had his camera operating.