Anger over mass kidnappings-for-ransom, a decade-long Islamist insurgency and a crackdown on protesters in Lagos last October has fueled demands for the government of President Muhammadu Buhari to do more to tackle violence and insecurity.
There was a heavy police presence in the country's two major cities as several hundred people gathered to protest on Democracy Day, which marks Nigeria's move to civilian rule more than 20 years ago.
Reuters witnesses in Lagos and Abuja saw police shooting their guns into the air and firing tear gas into the crowds to disperse the demonstrators, who held placards and chanted "Buhari must go".
"We cannot continue like this... all the bad governance must stop," said protester Samson Okafor in Lagos, where teargas cannisters smouldered in the street as police shouted at demonstrators to leave the scene.
Officers were also seen smashing mobile phones confiscated from protesters, some of whom criticised the government's decision to suspend access to Twitter after the social media platform removed a recent post by Buhari.
Police did not immediately respond to requests for comment.
Before fleeing under clouds of tear gas, demonstrators in Abuja marched with banners reading "#Buhari Must Go" and other slogans denouncing rising insecurity and the country's 33.3% unemployment rate.
Some also carried placards demanding the freedom of Ibrahim Zakzaky, the imprisoned leader of banned Nigerian Shi'ite group the Islamic Movement of Nigeria.