Sanaa, Yemen (CNN) -- A series of explosions rocked the Yemeni port city of Aden ahead of a presidential election Tuesday, but no injuries were reported, security officials said.
The blasts took place in separate neighborhoods late Monday, only hours before polls were set to open. In one neighborhood, Mansoora, about five minutes of gunfire accompanied the explosion, but no one was hurt, two security officials confirmed.
Security had been tightened in Aden ahead of Tuesday's vote, which features only one candidate, Vice President Abdurabu Mansur Hadi. Hadi took over Yemen's government when longtime President Ali Abdullah Saleh handed over power following a year of unrest, but he insisted on standing for election to make his presidency official.
At least 10 new checkpoints had been set up in Aden to bolster security ahead of the vote, and the head of operations for the Supreme Committee for Elections and Referendum said last week that more than 80,000 members of Yemen's security forces would be posted at the 32,000 polling places.
Yemen, on the southeastern corner of the Arabian Peninsula, has a population of almost 25 million and has struggled for years with separatist movements.