Divers located the body of a young boy on Monday as they resumed their search for missing passengers after an overcrowded boat carrying Muslim pilgrims sank on Thailand's Chao Phraya river, leaving at least 15 people dead.

The accident happened on Sunday afternoon near the ancient city of Ayutthaya, a popular tourist attraction, when a boat packed with pilgrims returning from a mosque hit a concrete bank in strong currents.

Scores of people lined the bank on Monday morning as divers plunged into the swollen, brown waters for the grim task of searching the partially-submerged pleasure boat for the missing.

Distraught relatives wept as the body of an eight-year-old boy was pulled from the wreckage and laid in a white plastic sheet, an AFP team on site reported.

Rescuers used a white board to keep track of those still missing which by lunchtime stood at 13 named individuals, six of whom were children.

Ayutthaya deputy governor Rewat Prasong said the confirmed death toll stood at 15 with 14 people hospitalised. The dead were not thought to include any foreigners.

The boat's captain is in custody and faces a negligence charge after allowing the double-decked vessel to become overcrowded, police told AFP.

"The boat has permission to carry about 50 people but it was carrying more than 100 people," said Ayutthaya police chief Sudhi Puengpikul.

Disaster struck as the boat returned from a memorial for a Muslim scholar at an Ayutthaya mosque. 

Television footage showed the boat stopping abruptly as it appeared to hit the concrete bank, and sinking in seconds.

Thai broadcasters showed desperate scenes of the aftermath of the accident as passengers were pulled from the water while rescuers attempted to resuscitate stricken people.

- Safety lapses -

Many of the dead were trapped on the lower deck of the boat, which ran into trouble agonisingly close to safety.

Officials said its proximity to the bank may have prevented the toll from being even higher.

Despite its wealth compared to regional neighbours and huge tourism sector, accidents are common on Thailand's public transport network. 

Safety regulations are often weakly enforced, including on boats, with overcrowding, sinkings and crashes common -- particularly in busy tourist areas.

According to World Health Organization, Thailand has the world's second highest road fatality rate after Libya.

The Thai junta has got tough on breaches of many laws, but has so far failed to fix the chronic safety lapses in the country's transport system.

The Chao Phraya, the main river that flows through Bangkok, is a key commuting artery, filled with often packed boats plying the waterways at breakneck speed.

It runs through Ayutthaya, the ancient Thai capital whose riverside is studded with the remains of Buddhist temples.

Thailand's reputation as the "Land of Smiles" has suffered in recent years amid accidents, crimes against foreigners and political unrest.

But visitors keep coming.

A record high of nearly 30 million travelled to the kingdom in 2015, a number boosted by a surge in mainland Chinese tourists, with some 33 million expected this year.

The junta government this week said they expected tourism to account for as much as 17 percent of GDP this year.

Source: AFP