WASHINGTON >> Authorities issued a shelter-in-place order and searched Senate office buildings near the U.S. Capitol today after a 911 call warned of a possible active shooter. But a floor-by-floor search of the three buildings found nothing, and Capitol Police Chief Tom Manger said the cause of the security scramble “may have been a bogus call.”

“We found nothing concerning,” he said. “We got nobody who actually heard shots and certainly no victims.”

The incident comes amid heightened security concerns created by former President Donald Trump’s indictment on charges relating to his attempts to overturn the results of the 2020 presidential election. Trump is due in federal court Thursday just a few blocks from the Capitol.

Manger said Washington’s multiple law enforcement agencies had been planning “for a couple weeks now” for a possible indictment and had “a security plan in place” in case Trump supporters attempt to disrupt the legal proceedings.

The lockdown today started when local police received a call around 2:30 today warning of a “heavyset Hispanic male wearing body armor” inside the Hart Senate Office Building, one of three structures near the Capitol housing offices for senators and their staffs.

Capitol Police began a search, going floor by floor through the massive buildings.

Inside the Russell Senate Office Building, officers evacuated the hallways and shouted at people to run outside and away from the building. Outside, tourists watched as dozens of police cars surrounded the area. Staff and journalists working in the building received an email instructing them to take shelter in a locked room, remain quiet and silence all electronics.

Manger said about 90 minutes later that all three Senate office buildings had been cleared and the call appeared to have been false.

Both the House of Representatives and the Senate are currently on recess and the office buildings are generally less crowded than usual.