A Hampshire Fire and Rescue Service spokesman said it had received more than 20 calls about the smell, mostly in the Portsmouth area, with reports that it had been noticed as far north as Basingstoke and Andover and as far west as Ringwood.
Group manager Tony Deacon said:
Our control room has dealt with a number of calls reporting the unpleasant gas smell.
We want to reassure the public that the gas presents no threat to health and is completely harmless.
We would also like to remind the public that if they suspect they are dealing with a genuine gas emergency in their home or building, they should call the National Gas Emergency Number on 0800 111999.
More top news
Demonstrators gathered outside the National Press Club to oppose a group of Trump supporters who were staging a "DeploraBall".
Rosalind Brotherton initially started working at a school canteen but after studying part time is now in charge of a primary school.
The unexploded bomb was found near the Houses of Parliament and led to disruption in central London overnight.