Summary:
A lockdown at a university in Indiana has been lifted, the school's Twitter account says.

Full article:
A lockdown imposed Tuesday afternoon at Indiana University-Purdue University Indianapolis has been lifted, according to the school's Twitter account. Students and staff at the university had been asked to take shelter earlier Tuesday afternoon while police investigated a report of an armed person on campus. According to the school's Twitter account and website, students were to "remain in shelter location until an All Clear is received." That all-clear message came at 4:36 p.m. "Now returning campus to normal operations," the tweet read. The school did not say whether any gunman had been found. About 30,000 students go to the school in Indianapolis.