Image copyright Getty Images Image caption Protesters have set up a tent city on campus

Police at the University of Missouri have arrested at least one man after death threats were posted online against black students.

Officials linked 19-year-old Hunter Park to some of the threatening posts but did not say how.

The university increased security but said there is no "immediate threat".

Mr Park's arrest comes days after University President Tim Wolfe was forced out, accused of not doing enough to address racism on campus.

Threats mostly came from users of the anonymous messaging app Yik-Yak.

Yik Yak condemned the threatening messages and said in a news release that the company works alongside authorities to help in investigations and it may share information with law enforcement.

Mr Park was not on campus or nearby when posting the message, police said.

He lives in Rolla, Missouri, about 100 miles (161km) south of the Columbia campus and is a student at the Missouri University of Science & Technology, the school confirmed.

"I'm going to stand my ground tomorrow and shoot every black person I see," one anonymous post read on Yik Yak.

Image copyright AP Image caption Police said Hunter Park, 19, made threats using the anonymous messaging app Yik Yak

Another warned black students simply not to come to campus the next day and another said "we're waiting for you at the parking lots... we will kill you."

Before the suspect was apprehended, protest leaders said the university administrators were not doing enough to address the threats against minority students.

One black student tweeted an email conversation with his professor in which he told the professor he was scared to come to class because of the threats.

"The only way bullies are defeated is by standing up to them ... If we cancel the exam, they win; if we go through with it, they lose," the professor wrote.

In recent weeks, students staged a sit-in on a university plaza and one graduate student participated in a hunger strike, calling for Mr Wolfe's resignation.

Among the offences black students have complained about are that a swastika drawn in faeces was found in a dormitory bathroom and that they are subjected to racial slurs by passerby in cars and on campus.

Mr Wolfe stepped down after the university's American football team joined the cause, threatening not to play until action was taken to address racial issues on the mostly white campus.