ABOARD JINGGANGSHAN, April 7 (Xinhua) -- Four Chinese ships continued the search for missing Malaysia Airlines Flight MH370 on Monday, scanning an expanded sea area in the Indian Ocean in which a pulse signal consistent with flight recorders had been detected earlier.
The flotilla consists of two Chinese naval ships, Jinggangshan and Kunlunshan, Donghaijiu 101 and Haixun 01, which picked up the pulse signal last week.
The two Chinese naval vessels carried out a round-the-clock visual lookout in the new target area, located more than 600 nautical miles (1,111 km) off Australia's western coast.
Four speedboats were also dispatched again to the suspicious spot of 25 degrees south latitude and 101 degrees east longitude, where the pulse signal was detected.
On Friday, Chinese patrol vessel Haixun 01 detected a pulse signal with a frequency of 37.5 kHz -- the same as those emitted by flight recorders -- in the new search area, and re-detected the pings for 90 seconds on Saturday just 2 km away from the original spot.
However, neither of the signals has been confirmed as related to the missing plane, said the China Maritime Search and Rescue Center.
Since MH370 disappeared early March 8 with 239 people on board from Kuala Lumpur to Beijing, the Chinese navy has sent nine ships to waters in the Gulf of Thailand, near Sumatra Island, and off Australia's southwestern and western coasts, scouring an area of around 340,000 square km.
Despite massive multinational efforts, no hard evidence has so far been acquired about the whereabouts of the ill-fated jetliner.