NIAMEY (Reuters) - Seven poll workers were killed during Niger’s presidential vote on Sunday when their vehicle struck a landmine, an election official said, marring a day meant to usher in the country’s first democratic transition of power. The West African country regularly suffers attacks by Islamist militants and had stepped up security to protect the poll, in which ruling party candidate Mohamed Bazoum is facing former president Mahamane Ousmane. A vehicle belonging to the electoral commission (CENI) and carrying election workers to their polling stations hit a mine in the rural commune of Dargol in the southwest, said Harouna Mounkaila, the vice president of CENI’s local branch. “They were leaving to drop off the ballot boxes and the members of the polling station,” Moukaila told Reuters. Three other workers were seriously wounded, he said. Dargol is about 80 km (50 miles) from the border with Mali, a hotbed of militant activity. An attack on two villages near the border in January killed at least 100 civilians, the worst such incident in recent memory. Niger’s twin security crises - one near its western border with Mali and Burkina Faso, where militants linked to al Qaeda and Islamic State operate, and the other along the southeastern border with Nigeria, where Boko Harm is active - were the dominant campaign issues. CONTINUITY VERSUS CHANGE In the first round on Dec. 27, ruling party candidate Bazoum, a former interior and foreign affairs minister, won 39.3% of the vote to Ousmane’s 17%. Bazoum then won the endorsements of the candidates who came third and fourth in the first round. In the capital Niamey, the vote appeared to go smoothly. President Mahamadou Issoufou, who is stepping down after two five-year terms, hailed the historic nature of the election in a country that has seen four coups since independence from France in 1960. Election workers began to count ballots shortly after polls closed at 7 p.m. (1800 GMT). Results are expected by Friday. Earlier in the day, Bazoum had projected confidence. “I hope that luck is on my side, but I have many reasons to believe it is indeed,” he said. Bazoum, 61, has vowed to continue Issoufou’s policies. The 71-year-old Ousmane, Niger’s first democratically elected president, who was ousted in a 1996 military coup, has promised to bring change and tackle corruption. “The vote is in every way between continuity and change,” said Mahamadou Harouna, a 30-year-old student who declined to say how he voted. One of the world’s poorest nations, Niger has struggled with drought, floods, coronavirus and weak prices for its main export, uranium. Ousmane has rejected the conventional wisdom that Bazoum is the favourite, alleging that the ruling party candidate’s first-round margin was due to fraud, without providing evidence. “If the citizens ever notice fraud again, I fear the situation will be difficult to manage,” he said after voting.