CAIRO (AP) — Egyptian authorities have detained at least 73 campaign volunteers for a challenger to incumbent President Abdel Fattah el-Sissi in the December election, a rights group said Tuesday.

The Egyptian Initiative for Personal Rights said the detainees were volunteers working for presidential hopeful and critic Ahmed Altantawy. The dozens of supporters face a variety of charges including joining a terrorist group — government parlance for the outlawed Muslim Brotherhood — and spreading false news. Seven of them remained in detention as of Monday, the group said.

Egypt’s chairman of the National Election Authority, Waleed Hamza, on Monday announced details of elections due by next year, saying the presidential polling would be held over three days in December. The outcome is widely anticipated to be a foregone conclusion in favor of the incumbent el-Sissi. The former defense minister has led the country since 2014 and has faced criticism from the West over his country’s human rights record and crackdown on political dissent.

Altantawy, who announced his candidacy in the spring of this year, is part of a small group of politicians who have stepped up to challenge el-Sissi. Altantawy is a former lawmaker who returned to Egypt from Lebanon in May, who has said he wants to provide a democratic alternative to el-Sissi’s government, describing its treatment of political opponents as unlawful and unjust.

Altantawy has previously complained that Egyptian security agencies have harassed his campaign staff and family, and also claimed that authorities have spied on him through cutting-edge technology.

El-Sissi led the military overthrow of an elected but divisive Islamist president in 2013 amid street protests against his one-year rule. Since then, authorities have launched a major crackdown on dissent. Thousands of government critics have been silenced or jailed, most of them Islamists but also many prominent secular activists, including some of those behind the 2011 uprising that toppled longtime autocrat Hosni Mubarak.

El-Sissi was first elected in 2014 and then reelected in 2018 for a second four-year term. Constitutional amendments, passed in a referendum in 2019, added two years to his second term, and allowed him to run for a third, six-year term.

Other presidential candidates who have thrown their hat into the ring publicly include Abdel-Sanad Yamama, head of the Wafd party, one of Egypt’s oldest; Gameela Ismail, head of the liberal Dostour, or Constitution, party; and Farid Zahran, head of the Egyptian Social Democratic Party.