The prosecution has requested arrest warrants for seven South Korean university students for breaking into the residence of the top United States envoy in South Korea.

The Seoul Metropolitan Police Agency said on Sunday that the police originally sought arrest warrants for nine students on Saturday but the prosecution requested warrants for just seven of them.  The police said it is hard to disclose why the warrants were not sought for the two.

The warrant request by the police came a day after 17 student members of a progressive civic group broke into the residence of U.S. Ambassador Harry Harris in central Seoul by climbing over its wall using a ladder.

The students staged a surprise protest criticizing the U.S. demand for a five-fold increase in South Korea's contribution to the upkeep costs of U.S. troops.

The 17 students were taken into police custody along with two others who attempted to break into the residence.

Police requested arrest warrants for nine students and released ten others at around 10 p.m. Saturday.