After he was killed, the authorities ordered the university campus shut, apparently to prevent protests.

The company worked to distribute correct information in an effort to prevent widespread protests.

The bodies were hidden or destroyed to prevent protests at home and abroad.

Troops were sent to Yerevan to prevent protests against the decision.

"We urge the Egyptian authorities not to prevent peaceful protests or block communications including on social media sites."

On Friday, police were deployed in the streets to prevent new protests.

To prevent protests and disturbances, the Home Office had ordered several detachments of police to stand by.

Troops were deployed in Yerevan to prevent protests to the decision.

Universities have been closed since December 1996 to prevent protests.

The authorities also cut telephone lines and seized residents in an attempt to prevent protests during the meeting of Palestinian leaders.