The captain of a cruise ship was formally arrested on Saturday after a Hungarian court issued an arrest warrant following the ship's deadly collision with a smaller tourist boat.

The court approved the arrest of the 64-year-old Ukrainian captain, identified as Yuriy C, on charges of negligence and carelessness over the accident.

The court ordered his arrest for 30 days with the possibility of release on bail set for 15 million forint or 59 million won.

The captain was initially detained and questioned by Hungarian police right after the sinking of the tourist boat Hableany on the Danube River on Wednesday.

A lawyer for the captain said he is in an unstable condition after the accident and would like to convey his deep sympathy to the victims' families.