Japan on Monday continued to search for seven missing crew members of two Maritime Self-Defense Force (MSDF) helicopters that are believed to have collided over waters hundreds of kilometers south of Tokyo, with defense officials saying there was no indication of aircraft issues amid the possibility that an alert system may not have been activated.

Defense Minister Minoru Kihara told a televised news conference Monday that the ministry was analyzing data from two flight recorders that were recovered a day earlier, after the two SH-60K helicopters crashed during nighttime anti-submarine training about 270 km east of Torishima in the Izu Islands late Saturday.

The crash killed at least one crew member and left seven others missing.