KUALA LUMPUR (Reuters) - Malaysia will ask three social media and Internet companies to curb content in the interest of public safety, the communications minister said on Monday.

The request is the latest attempt by Malaysia's embattled government to quell dissent after Prime Minister Najib Razak became embroiled in controversy over big debts at state fund 1Malaysia Development Berhad (1MDB).

The Malaysian Communications and Multimedia Commission will meet Facebook, Google, and Twitter "soon to seek their cooperation to stem the increasing tide of false information and rumors", Communications Minister Salleh Said Keruak wrote on his blog.

"The online environment is not a lawless space and action can be taken against anyone found to have breached the law, including in the online space," he added, without elaborating.

Najib, 62, has been under pressure since reports emerged that nearly $700 million were transferred into his personal accounts. Reuters has not verified those reports.

The prime minister has denied wrongdoing and the anti-graft agency investigating the funds transferred into his accounts said the money was a "donation" and not from 1MDB.

Authorities are investigating allegations of graft and financial mismanagement at 1MDB, a fund with debts of more than $11 billion. Najib chairs the fund's advisory board.

The prime minister sacked his deputy and other ministers last month after they questioned him publicly about the 1MDB affair. The government has suspended two newspapers and a website that were reporting on 1MDB.

Pro-democracy activist Mandeep Singh Karpall said the government was trying to control freedom of expression by clamping down on social media where many Malaysians express political views, especially younger people.

"They're doing it to create a climate of fear," said Karpall, acting manager of the pro-democracy group Bersih that is organizing an anti-government rally in the capital this month.

A Google spokesman in Kuala Lumpur said the Internet giant was "always in conversation with" the Malaysian Communications and Multimedia Commission but he declined to comment on the request from the government on curbing content.

Facebook and Twitter were not immediately available for comment.