Abuja, Oct 23 : Gunfire has erupted and jailbreaks have been reported in Nigeria, as unrest over the shooting of protesters in the country's biggest city Lagos continues. Rights group Amnesty International has said security forces killed at least 12 people in Lagos on Tuesday, the BBC reported. Nigeria's army has denied killing demonstrators in the Lekki area, provoking more anger. The protests began about two weeks ago with mostly young people demanding the disbandment of a notorious police unit. The Special Anti-Robbery Squad (Sars), which had been at the centre of protests against police brutality, was dissolved on October 11. Using the hashtag #EndSars, protesters rallied crowds to the streets. The shooting has spurred global calls for those responsible to be held to account. In a short televised address on Thursday, Nigerian President Muhammadu Buhari urged protesters to stop demonstrating and instead engage with the government "in finding solutions". He made no mention in the speech of the shooting of protesters in Lagos. Earlier, Nigeria's vice-president promised justice for victims shot during the protests. Lagos and other parts of Nigeria have seen buildings torched, shopping centres looted and prisons attacked since the shooting. The state government in Lagos imposed an indefinite round-the-clock curfew on the coastal city's 20 million inhabitants on Tuesday evening. Other states have taken similar action, including Anambra, which ordered a 24-hour curfew on Thursday. /IANS