BRUSSELS (AP) — The European Union reached an agreement Tuesday with some of the world's biggest social media firms, including Facebook and Twitter, on ways to combat the spread of hate speech online.

Under the terms of a code of conduct, the firms, which also include YouTube and Microsoft, have committed to "quickly and efficiently" tackle illegal hate speech directed against anyone over issues of race, color, religion, descent or national or ethnic origin. The sites have often been used by terrorist organizations to relay messages and entice hatred against certain individuals or groups.

Among the measures agreed with the EU's executive arm, the firms have said they will establish internal procedures and staff training to guarantee that a majority of illegal content is assessed and, where necessary, removed within 24 hours. They have also agreed to strengthen their partnerships with civil society organizations who often flag content that promotes incitement to violence and hateful conduct. The European Commission and the firms have also agreed to support civil society organizations to deliver "anti-hate campaigns."

"The internet is a place for free speech, not hate speech," said Vera Jourova, the EU commissioner responsible for justice, consumers and gender equality. She added that the code of conduct, which will be regularly reviewed in terms of its scope and its impact, will ensure that public incitement to violence to hatred has "no place online."

The firms themselves say there's no conflict between their mission statements to promote the freedom of expression and clamping down on hate speech.

Twitter, which has been at the center of much of the hate speech that's spread online over the past few years, says it will continue to tackle the issue "head-on" along with partners in industry and civil society.

"We remain committed to letting the Tweets flow," said Twitter's European head of public policy Karen White. "However, there is a clear distinction between freedom of expression and conduct that incites violence and hate."

And Facebook's head of global policy management Monika Bickert urged the company's 1.6 million users to use the site's in-built reporting tools in the event they find content they consider unacceptable.

"Our teams around the world review these reports around the clock and take swift action," she said.