The Ilinden - pictured here last year - had a permit to carry 45 passengers
At least 15 people have died after a sightseeing boat sank in Lake Ohrid in south-western Macedonia.
The Ilinden sank about 200m from the shore - reportedly within four minutes. About 40 passengers have been rescued.
The Bulgarian government says the dead were all its nationals. The captain of the boat said there was a "loud crack" before the boat sank, police say.
Police have described the incident as "an enormous tragedy". Lake Ohrid is Macedonia's best known tourist resort.
Earlier reports said 19 people had died and indicated that the cause could have been overcrowding, with 73 passengers on board, when the boat only had a permit for a maximum of 45.
Rescuers search the waters of Lake Ohrid
However, later on Saturday Macedonian officials lowered the death toll to 15 and said there had been about 57 passengers on board.
In neighbouring Bulgaria, the government information office said the dead included one child.
"The 23-year-old skipper and his deputy have been questioned about the incident," Macedonian police spokesman Ivo Kotevski told the Associated Press news agency.
"In their first statements they said that a loud crack was heard toward the rear before the boat sunk rapidly."
Cries of help
The tourists had been on their way to the St Naum monastery complex when the 30m (98 feet) vessel broke in two and sank at about 1100 (0900 GMT), according to witnesses.
"We were in a speed boat and we saw the boat sinking. We just turned around and we saw people crying for help," an eyewitness told BBC Macedonian.
"When we got there, 10 were already dead. We took seven with us, we thought we could save more but it was too late."
Another witness told the BBC: "Around 1030 I went to the beach, and all of a sudden, I heard cries of 'Help! Help me, help me!' and we saw how the forward part of the boat had sunk in the water.
"I have a small dinghy and with a friend we went towards the boat, then two more small boats came along.
"It was lucky that there were other small boats who came along, and threw life-saving vests and took the survivors on board.
Police divers are on the scene.
A BBC correspondent in the region says accidents like this on Lake Ohrid are extremely rare.
Macedonia's transport minister had offered his resignation.