Twitter says it has suspended more than 125,000 accounts since mid-2015 "for threatening or promoting terrorist acts," BBC News reports.

In a blog, the U.S.-based firm said the accounts "primarily related to ISIS" (the so-called Islamic State group).

"We condemn the use of Twitter to promote terrorism," it said, adding that it had increased its report reviewing teams to react faster.

Twitter has more than 500 million users around the world.

"We have already seen results, including an increase in account suspensions and this type of activity shifting off of Twitter," the company said.

It added that it was co-operating with law enforcement bodies "when appropriate" as well as other organizations.

Governments around the world - including the U.S. - have been urging social media companies to take more robust measure to tackle online activity aimed at promoting violence.