BANGKOK, June 26 (Xinhua) -- Rescuers are still searching for 12 schoolboys, aged 11 to 16, and their soccer coach in a flooded cave in northern Thailand, according to reports.

Waters inside the cave are being pumped out to give Navy Seal divers enough room to operate.

Officials still believed the missing are alive somewhere safe and deep inside the cave, away from the flood caused by the heavy rain.

Rescuers are working day and night to reach the missing children, Thailand's Interior Minister Anupong Paojinda said, as quoted by the Associated Press.

Rescuers have found shoes and bags in the second chamber behind the cave entrance, while footprints and handprints were also found inside the cave complex where the flood didn't reach.

Parents of the missing children have been waiting at the entrance of the cave, while the whole country is praying for the safety of the missing ones who have been trapped for over three days.

The missing 13 people entered the Tham Luang Nang Non cave in Chiang Rai province on Saturday afternoon, and were feared cut off by rising water levels in the cave due to the heavy rain.

Rescue operations began later that day after a mother of one of the boys called the police and reported that her boy did not return from soccer practice.

The cave complex is thought to be about six to eight km long and contain some large chambers as well as passageways with changes in elevation.

The 25-year-old coach has been organizing frequent excursions for his soccer team, and they have entered the cave before, according to local police.

"But they didn't think that going in at this time would be dangerous," Chote Narin, a police officer at Mae Sai district of Chiang Rai province, told the Associated Press.