ISTANBUL — Turkey’s deputy prime minister on Monday raised the possibility that the army could be called in to help quell the continuing civil unrest, the latest sign of the government’s impatience and officials’ hardening stance against a nearly three-week-old protest movement.

The comments by the deputy prime minister, Bulent Arinc, followed days of intensifying street violence and signs of a broadening government crackdown that included the arrests of journalists as well as medical workers who have been treating protesters. Demonstrations continued Monday in several Turkish cities, led by unions that had called for a nationwide strike.

Prime Minister Recep Tayyip Erdogan has reacted with growing annoyance to the protests, which have saddled him with his most serious domestic challenge in a decade and embarrassed him abroad. In recent days, Mr. Erdogan has seemed to rule out a compromise with a movement that started with protests against the planned destruction of an Istanbul park, and that grew by tapping into broader complaints over what critics see as Mr. Erdogan’s authoritarian manner.

On Monday, the prime minister’s subordinates detailed new measures aimed at stopping the protests. The interior minister, Muammer Guler, said that new regulations were being prepared to police social media outlets, aimed at people who use Twitter or Facebook for “inciting people or coordinating and directing events that would cause social incidents or endanger material and physical public safety through manipulative, false news.”