Bangladesh’s US-Bangla Airlines has suspended its flights to Nepal indefinitely due to a shortage of aircraft, days after one of its planes crashed as it tried to land in the Nepali capital and killed 51 people.

The airline and airport authorities in Kathmandu have traded blame for Monday's accident, the Himalayan nation's worst air crash since a 1992 crash of a Pakistan International Airlines plane killed 167 people.

"We had to stop flight operations between Dhaka and Kathmandu due to a shortage of aircrafts,” airline spokesman Kamrul Islam told Reuters on Thursday.

He said flights on other domestic and international routes would operate as normal.

The Bombardier Q400 aircraft was carrying 71 people from the Bangladeshi capital. There were 20 survivors.

The crash investigation might take a year to complete, said Air Vice Marshal Naim Hassan, chairman of the Bangladesh's civil aviation regulatory agency.