The bus was going from Konkan to Borivali.
The bodies have been sent to Sadar hospital for post-mortem while injured have been rushed to the Jhanjharpur PHC for treatment.
The incident occurred on Monday.
12 in Mandi, 10 in Kangra; Himachal govt orders magisterial probe.
Chief Minister Raman Singh expressed grief over the incident Wednesday night.
Police said the bus carrying 38 passengers of Bharati Gananatya, a local jatra group, went off the hilly road and plunged into a 200-250 feet gorge at Tilebani Gayala ghat.
The bus, which was carrying 57 passengers, appeared to have hit a guardrail of the AP7 highway before cartwheeling across the road, slamming through a divider and landing on its side.
A while later, he found himself trapped in the mangled bus which was resting on its head after skidding off the road and doing two somersaults near Luvara village in Savarkundla taluka of Amreli on February 13.
Saiyed added that the bus had done only six lakh kilometres so it was considered “fit” and only after completing eight lakh kilometres they are scrapped.
Ujamsinh Shah, Sub-Inspector of Savarkundla Rural police, says, “On the day of the accident, Ghusar was assigned the Upleta-Mahuva route after 10 years.
That fateful day, Shailesh, a Class X student, saw his mother’s phone number flashing on his phone in the morning, but he could not take the call.
Anandiben Patel has offered only Rs 4 lakh as compensation in Navsari bus deaths.
The injured have been admitted to hospitals, police said.
The passengers included students, employees working in different private and government offices, who were on their way to Ukai from Navsari State transport depot.
Police said that heavy rains in the monsoon had washed away soil from the ends of the causeway and driver of the bus could not control the vehicle while negotiating a curve near it.