Authorities have found no evidence of an attacker or shots being fired while investigating a report of an active shooter at Howard University, Washington DC police have said.

They have lifted the lockdown on campus.

"We're on the scene @HowardU for the report of an active shooter," the DC Police Department posted on Twitter earlier in the day. "So far nothing confirmed. Take precautions if in the area."

The incident began to unfold at around noon on Tuesday.

Howard University said in a tweet that it had received an anonymous report of a “potential shooter on campus.”

“We took the call seriously and police are investigating,” the university said.

University President Wayne A.I. Frederick said there was no evidence of a shooting, as of 12.40 pm, according to the Washington Post.

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Mr Frederick said on Twitter that police are currently conducting a sweep of campus.

Some streets were closed in the area due to police activity.