Police have sought an arrest warrant for a South Korean man on charges of burning the national flag during last month's ceremony marking the first anniversary of the Sewol ferry sinking, officials said Sunday.

The 24-year-old man, only identified by his surname Kim, was accused of burning the national flag during the April 18 rally in downtown Seoul and trying to damage a police vehicle, the Seoul Metropolitan Police Agency said.

Thousands of people attended the ceremony to mark the first anniversary of the sinking of the ferry Sewol off the southwest coast that claimed 304 lives.

Violent clashes broke out later that night as authorities sealed off downtown Seoul with police buses. They were blocking demonstrators who tried to march to the presidential office to demand a more thorough investigation into the cause of the sinking.

Kim confessed that he burned the flag as he was angry about the government authority and it was not premeditated, officials said. 

Police claimed that burning the national flag in a public place is a serious crime and the suspect should be held in detention during the investigation considering that he discarded the clothes and shoes he wore during the rally in an attempt to hide evidence. (Yonhap)