Two leading U.S. dailies say South Korea’s tentative assessment that a torpedo likely caused the sinking of the “Cheonan” vessel has further raised speculation that North Korea was behind the incident.

The Wall Street Journal quoted on Sunday South Korean Defense Minister Kim Tae-young as saying that a heavy torpedo is the most likely cause of the sinking of the naval ship. The paper said that Kim’s statement has brought Seoul closer to declaring that the Cheonan was attacked by the North and hastening a delicate decision about what to do next.

The New York Times said South Korea’s statement on the cause of ship’s sinking inched the country closer to placing blame on North Korea and added urgency to the question of how the South might respond.

The report added that with the joint military and civic team’s investigation having yet to determine the cause of the Cheonan’s sinking, speculation on what caused the blast has ranged from a North Korean torpedo to an uncollected mine from the Korean War.