At least one person was killed and three other injured in two separate shootings at a historically Black university in North Carolina during its homecoming weekend, police said on Sunday.Both incidents took place on Saturday at Winston-Salem State University, assistant police chief Jason Swaim of the Winston-Salem Police Department said.However, authorities have yet to establish whether the shootings were connected.Police are investigating the incidents and have declared the campus safe. The lockdown imposed earlier has also been lifted. Swaim did not disclose whether any arrests had been made.“The investigation is still very early in its preliminary stages,” Swaim said at a press conference early Sunday.