Military and rescue authorities monitoring progress in the search for AirAsia Flight QZ8501 in the Mission Control Center inside the National Search and Rescue Agency in Jakarta on Monday. REUTERS/Darren Whiteside Australian search-and-rescue planes spotted objects in the sea within the search area for the missing AirAsia plane, but upon further investigation Indonesian officials have said that the objects are not from the jet.

An Indonesian helicopter reported two oil slicks within the search area as well, but officials later said that also wasn't tied to the missing plane.

Officials said earlier that the missing plane is likely "at the bottom of the sea," but no debris has been found so far.

It's not yet clear what the objects seen in the water were. They were spotted about 700 miles from AirAsia flight QZ8501's last known position.

The search for the missing plane is in its second day. The plane went missing during a flight from Indonesia to Singapore shortly after asking to deviate from its planned flight path because of bad weather.

The flight crew lost contact with air traffic control at about 6:17 a.m. local time Sunday, about halfway through the flight. The plane was initially thought to have crashed near the Indonesian island of Belitung, which is near the plane's last known location.

The "suspicious objects" search teams spotted in the water were near Nangka island, according to the Associated Press.

The missing plane is an Airbus A320-200, a popular and generally reliable model. The plane is about six years old and is operated by AirAsia's Indonesian affiliate, which the Malaysia-based company holds a 48.9% stake in, CNN reports.

The missing plane carried 155 Indonesians, along with three people from South Korea and one each from Singapore, Britain, Malaysia, and France. The passengers included 16 children and one infant.

The AirAsia plane disappearance comes after two other major aviation disasters this year. Malaysia Airlines Flight MH370 disappeared in March and was never found. In July, Malaysia Airlines Flight MH17 was shot down while it was flying over Ukraine.

Crews have been searching for the AirAsia plane in the vicinity of its planned flight path: