A North Korean balloon carrying trash exploded over the South Korean presidential office in Seoul on Thursday, dumping filth over one of the capital city’s most heavily guarded premises.

The explosion happened in early morning and the contents were scattered across the compound where Yoon works, according to a statement from the presidential security agency. No contamination or security risk has been detected in the rubbish and the presidential office is working with the Joint Chiefs of Staff to keep an eye on further threats, it said.