Burkina Faso is beginning three days of national mourning after an attack by al-Qaida militants left at least 28 people dead.

In a message broadcast to the nation, President Roch Marc Christian Kabore said the people of Burkina Faso must unite in the fight against terrorism.

He also announced that security forces will be stepping up security checks at entrances to the capital, Ouagadougou, and other major towns, as well as along the country's borders.

The period of national mourning began Sunday, a day after Burkinabe and French forces ended a more than 12-siege at an upscale hotel in downtown Ouagadougou. When the gunfire and explosions finally stopped, authorities said 18 were killed in the hotel and 10 killed at a nearby cafe. The four attackers were also killed.