CAIRO — An explosion apparently targeting a bus filled with tourists near the pyramids of Giza in Egypt wounded at least 14 people on Sunday, according to security officials and the state-run news media.

The attack occurred close to a giant national museum that is under construction near the pyramids and that is scheduled to open next year. It was the second attack on tourists in Giza in six months, and it suggested that armed militants opposed to President Abdel Fattah el-Sisi were seeking to undermine his authority by hitting tourists at a time when he is planning a gala opening for the long-awaited institution.

There was no immediate claim of responsibility for Sunday’s attack. Previous violence against tourists has been claimed by the Islamic State’s Egyptian affiliate and by other armed Islamist factions opposed to Mr. el-Sisi.

Four people, including three Vietnamese tourists and an Egyptian guide, died in a bomb attack on a tourist bus in Cairo in December.