(Seoul) North Korea launched about 310 balloons weighted with garbage across its southern border overnight from Sunday to Monday, according to the South Korean military cited by the Yonhap agency, after the influential sister of Kim Jong-un promised a “new response.”

“The latest batch of garbage-laden balloons sent on Sunday contained waste paper and plastic, with no toxic materials detected so far,” the Joint Chiefs of Staff said, according to Yonhap. No other balloons were detected in the sky Monday morning, he added.