Delhi Tuesday outlined its plans to restrict the number of vehicles on its roads at the beginning of January, as the world's most polluted capital attempts to clean up its toxic air.

The government announced last week it will restrict private car use on alternate days on the basis of license plates from January 1, a measure to check air pollution levels in the Indian capital.

Following criticism that the plan lacked detail, Gopal Rai, Delhi's transport minister, told reporters at a press conference on Tuesday: "The restrictions will be initially for the first 15 days of January between 8 AM to 8 PM and will exclude Sundays. We will review the progress after the first phase is over."

"We will present a complete blueprint by December 25," he added.

The government will also conduct air monitoring at 200 locations to gauge the impact of the ban, he said, and formulate a long term policy on curbing air pollution in the city.

Volunteers, civil defence and police will be roped in to enforce the ban, he added, without specifying how violators will be tackled on the roads.

Air pollution in Delhi has reached alarming proportions, with some locations recording levels ten times more than permissible.

During winter months Delhi remains enveloped in a smoggy layer as cooler air and cloud trap pollutants.

There are more than 8.5 million vehicles on Delhi's roads with 1,400 new cars added every day.

The minister said a decision whether or not to include more than 5 million motorcycles and mopeds in the ban has yet to be taken, as he promised to strengthen the public transport system by introducing more buses and increasing the frequency of metro train services.

The ban has received a mixed response from the public, with political parties slamming the government for making a hasty decision, as the city lacks a robust public transport system.

But it has won accolades from many, including India's top judge, who offered his support to the scheme by taking a bus to work, and environmentalists, who say pollution levels are reaching dangerous levels.

Successive Delhi governments have faced flak for failing to clean up the filthy air, ranked as the worst in the world in a 2014 World Health Organization survey of more than 1,600 cities.

Several Chinese cities have slapped limits on car numbers because of congestion and pollution, but it is the first time an Indian city has implemented such a measure.

The issue has been in the spotlight this week as negotiators from 195 nations have gathered in Paris for talks billed as the last chance to avert the worst consequences of global warming.