Twitter Inc has shut down 360,000 accounts for threatening or promoting terrorist acts since the middle of 2015, the company said in a blog post on Thursday.

The microblogging platform has previously come under fire from Washington and third-party groups for not doing enough to stop accounts linked to Islamic State militants.

But, since February, it has suspended an additional 235,000 accounts, after halting 125,000 accounts since the middle of 2015, most of which were related to Islamic State.

Twitter said its daily suspensions of terrorism-linked accounts have jumped 80 percent since last year and that it has reduced its response time.

Watchdog groups praised Twitter's swift response to online celebrations from Islamic extremists glorifying a July truck attack in Nice, France, that killed more than 80 people.

The company relies primarily on user reports to identify offending accounts, and said it has increased the size of the team reviewing reports.

Although it says an algorithm cannot identify extremist propaganda, it relies on spam-fighting tools to help identify repeat offenders, including those who create new accounts when they are suspended.

"Our work is not done," the blog post said, adding: "Our efforts continue to drive meaningful results, including a significant shift in this type of activity off of Twitter."