By Dan Isaacs BBC correspondent in Lagos

The Nigerian authorities have announced further drastic measures to improve the safety of air travel in the country following the crash of a domestic airliner early this month in which up to 150 people lost their lives.

A ban has been announced on all airlines with only one aircraft in their fleet on the grounds that safety considerations are being strongly compromised by the economic necessity of continued business operation.

These are desperate measures by Nigeria's civil aviation authority to improve the safety and reliability of the airline business

This latest step could force the closure of many of the country's airlines - including, embarrassingly for the government, the domestic arm of the national carrier, Nigeria Airways.

Measures taken already - even before the official investigation into the Kano plane crash is completed - include the dismissal of a host of senior aviation officials and ban on all aircraft built before 1980.

Ruin

These are desperate measures by Nigeria's civil aviation authority to improve the safety and reliability of the airline business.

As a direct result, many of the airlines here face instant closure and economic ruin.

After years of decline, the national carrier, Nigeria Airways, has only one single aircraft flying domestic routes; the rest of its planes lie in various states of disintegration in a hangar at Lagos Airport.

So its domestic arm is a prime candidate for shutdown on safety grounds under the new regulations, although it does still have two leased planes flying international routes.

Less is more

Clearly, there is a strong feeling among the Nigerian aviation authorities that the industry is in a terrible mess, with lax safety standards and inadequate regulations.

The fervent hope among air travellers here is that after the dust has settled on the wholesale clear-out in the industry, there will be fewer, but safer aircraft flying around the country.

For those that can afford it, flying has become a daily and indispensable mode of transport in a country with no passenger train network, and roads that are considered to be among the most dangerous in the world.