A Thai official says the helmsman who operated a passenger boat that sank over the weekend has been arrested for violating navigation laws as the death toll climbed to at least 27 people.

The Marine Department official, who spoke on condition of anonymity because she was not authorized to release information, said Tuesday that the search was continuing for the two known missing passengers, a 2-year-old boy and a 70-year-old woman.

The boat was carrying over 100 Muslims home from a religious festival Sunday on the Chao Phraya river north of Bangkok. It sank rapidly after taking on water just a few meters from the riverbank.

Forty-four passengers were hurt.

Authorities previously said the passenger capacity was 50 and overloading was a suspected cause of the sinking.