World Athletics has banned transgender women from competing in elite female competitions from March 31 and tightened testosterone restrictions for other athletes, the governing body said on Thursday. 

World Athletics president Sebastian Coe said that the decision to exclude transgender women who had gone through male puberty was based "on the overarching need to protect the female category." 

The tighter measures around one of the most contentious and divisive issues in sport follow a similar move by World Aquatics in 2022.

World Athletics' council also voted to cut the maximum amount of plasma testosterone for athletes with Differences in Sex Development (DSD) in half, to 2.5 nanomoles per liter from five. 

DSD athletes will also have to reduce their testosterone levels below the new limit for a minimum of 24 months across all events to compete, double the previous time. 

The governing body had previously floated the option of transgender athletes being allowed to compete in the female category if they, too, maintained testosterone levels below 2.5 nanomoles per liter for 24 months.

Yet it said on Thursday that it became apparent there was little support within the sport for that proposal.

Coe announced the formation of a working group, which will be chaired by a transgender athlete, to further study the issue of trans inclusion.

The tighter testosterone rules will impact DSD athletes such as two-times Olympic 800m champion Caster Semenya of South Africa, Christine Mboma, the 2020 Olympic silver medalist in the 200m, and Francine Niyonsaba, who finished runner-up to Semenya in the 800m at the 2016 Olympics.

Semenya and others had been able to compete without restrictions in events outside the range of 400 meters through one mile but now will have to undergo hormone-suppressing treatment for six months before competing to be eligible.

(With input from agencies)