"On the morning of June 4, some residents of Dandong, in Liaoning province, were shot by a DPRK border guard on suspicion of crossing the border for trade activities, leaving three dead and one injured," he said at a regularly scheduled news conference. He used the acronym for North Korea's formal name, the Democratic People's Republic of Korea.
"China attaches great importance to that and has immediately raised a solemn representation with the DPRK. Now the case is under investigation," he said.
Dandong is a major shipping point and rail link for goods going into and out of North Korea from China.
Qin did not give any further information. There have been some reports in South Korean media on the incident, though North Korea has not acknowledged the shootings.
The two countries are close allies, and China rarely criticizes its neighbor publicly. China has been crucial to North Korea's survival, providing food, fuel, and investment. Last month, its reclusive leader Kim Jong Il paid a rare visit to China, traveling to Beijing in search of additional economic assistance.
In return, he agreed to return to six-party talks, hosted by China, on Pyongyang's nuclear weapons programs, though no date was set.
However, tensions on the Korean peninsula have been high since the sinking of the South Korean warship Cheonan in March that left 46 sailors dead.
An international investigation has blamed North Korea for the sinking, but China has resisted pressure to condemn Kim Jong Il's regime. Instead, it has urged both the Koreas to show restraint.
On Tuesday, Qin again urged all parties to exercise calm in the wake of South Korea formally bringing the incident before the United Nation's Security Council last week.
"China calls on all parties to exercise restraint and calm so as not to further escalate the tensions," he said. "China also upholds peace and stability on the peninsula. We always adhere to that position."
The China-North Korea border is an area of major activity, with many impoverished North Koreans defecting to South Korea via the Chinese border, in part because of the difficulty of crossing the Demilitarized Zone. More than 16,000 have defected to South Korea since the Korean War. Last year, about 2,800 North Koreans arrived in the South, up from about 2,500 in 2007.
In March 2009, two American journalists were seized near the border town of Dandong. The two, Laura Ling and Euna Lee, had crossed into North Korea while reporting on a story about North Korean women forced into the sex trade or arranged marriages when they defected to China. They were nabbed by North Korean soldiers after they had already returned to Chinese soil. They were later released.