Congo's veteran opposition leader Etienne Tshisekedi has flown home after a two-year absence in Europe. Elections are due in November with President Joseph Kabila barred from running for a third term.
Cheering crowds greeted a visibly frail Tshisekedi (pictured center above) after he flew into Kinshasa on Wednesday. He had left the Democratic Republic of Congo in 2014 for medical treatment in Belgium.
Incumbent President Kabila has faced opposition accusations of wanting to delay the 27 November poll in order to cling to power. Tshisekedi was runner-up in 2011, a vote observers said was marred by fraud.
Kabila, who is constitutionally barred from a third term and is required step down this year, has been in power since succeeding his assassinated father, Laurent-Desire Kabila, in 2001.
His government has said logistical and budgetary constraints are the reason for the delay. The electoral commission has said it needs more time to prepare the election.
Frail on arrival
Tshisekedi, who leaned on his son as he disembarked slowly at Kinshasa's main airport, is scheduled to speak at an opposition rally on Sunday.
"The return of Tshisekedi represents the beginning of the departure of Kabila," said another opposition leader, Martin Fayulu.
Crowds of people looked on from rooftops and along the airport highway.
Another challenger warned
On Monday, Congo's Justice Minister Alexis Thambwe Mwamba warned a former Kabila ally turned presidential challenger, Moise Katumbi, who left the country in May, that if he returned, he would be jailed.
Katumbi, a tycoon, had been facing a jail term for alleged fraud and accusations of endangering state security.
Opposition meeting in Brussels
In 1982 - during the rule of autocrat Mobutu Sese Seko - Tshisekedi set up Congo's first opposition platform, the Union for Democracy and Social Progress (UDPS).
In June, Tshisekedi led a meeting in Brussels of opposition parties. Last Sunday, he said his UDPS and allied parties would not participate in a dialog led by the African Union's designated facilitator, Edem Kodjo, Togo's former prime minister.
Less violence, more rigging
On Monday, Nic Cheeseman, an African studies professor at Britain's Oxford University, said election violence had become rarer, but poll rigging remained rife.
"Leaders are becoming more and more aware of how they rig elections, and they are better and smarter at doing it," said Cheeseman, the founder of the journal "Africa Affairs."
Since 2015, around 20 presidential elections have been held across the African continent, with questions hanging over half of them.
An electoral expert with the International Organization of La Francophonie, Malian Siaka Sangare told the news agency AFP that there had been "some advances" in terms of less violence but "big challenges" remained ahead.
French Africa expert Antoine Glaser said, "some heads of state" had learned how to manage the "democratic theater" of elections by using their clans to retain power.