Dakar, Muharram 08, 1437, October 21, 2015, SPA -- Police fired tear gas and warning shots Tuesday in the Congolese capital Brazzaville at demonstrators opposing a planned referendum on a constitutional reform, the radio station France24 reported, according to dpa. There were at least two confirmed deaths and dozens injured in the unrest, the US State Department said. The US "strongly condemned" the violence, US State Department spokesman John Kirby said. The protesters say the reform is aimed at keeping President Denis Sassou Nguesso in power. Demonstrators - estimated to number in the thousands - burned tyres and erected barricades, defying a ban on public meetings, witnesses said. Rallies were held in other cities of the west African country, according to Radio France Internationale. The referendum scheduled for Sunday would remove age and term limits preventing Nguesso, 71, from seeking another term in 2016 elections. Kirby called on Nguesso to postpone the referendum to defuse the current tensions. He said the US believed that respecting term limits was "essential to democratic development and long-term stability." Nguesso has ruled Congo-Brazzaville since 1997. Previously he was president from 1979-92. --SPA 00:27 LOCAL TIME 21:27 GMT www.spa.gov.sa/w