Pro-European Union activists argue with riot police near a Svyatoshin police station in Kiev, Ukraine, Saturday, Jan. 11, 2014.

KIEV, Ukraine - Ukraine's ex-interior minister turned opposition leader was injured in a scuffle Saturday between police and anti-government activists, reflecting the high level of tensions after weeks of anti-government protests in the nation's capital.

Yuri Lutsenko, a top organizer of the mass protests that have gripped Kiev, was injured when he tried to intervene in a confrontation between riot police and opposition activists in the early hours.

The clashes erupted outside a court after it set six-year prison terms for three ultra-nationalist activists convicted of planning to blow up a statue in 2011.

Ukraine's top human rights official said 11 people were hospitalized after the clashes.

The Prosecutor General's office said it had launched a probe into allegations of abuse of authority by riot police officers.

The Interior Ministry said the scuffle erupted when demonstrators upset over the verdict tried to block the passage of a prison truck carrying the convicts. About 20 police officers were injured in the clashes, the ministry said.

The incident is likely to further fuel anger against President Viktor Yanukovych, who has faced protests over his decision to freeze ties with the West and move closer to Russia. Many of the protesters are Ukrainian nationalists angry about the president's tilt toward the country's powerful neighbor.

The protests on Kiev's main square, which were further fueled by a violent police crackdown on demonstrators, peaked at hundreds of thousands last month.