Kampala, Uganda (CNN) -- Dozens of people were injured Thursday when supporters of opposition leader Kizza Besigye clashed with security forces and police who were accompanying his convoy from the airport to the capital.
At least 39 people were hurt in the protests, according to the Red Cross.
As Besigye's convoy was inching toward Kampala -- it had gone only half of the 40 kilometer (25 mile) distance in five hours -- a convoy carrying newly sworn-in President Yoweri Museveni and heads of state who had flown in for the inauguration was on the same road, going the opposite way, to the president's official residence near the airport.
Police fired tear gas and live ammunition near the protesters, according to a journalist on the scene, and they briefly blocked reporters from getting near the skirmishes. Both Besigye supporters and security personnel were injured.
Besigye was returning from Kenya, where he'd gone to seek treatment for injuries suffered two weeks ago when police pulled him from a vehicle during protests over the rising cost of living in Uganda.
The opposition leader encountered problems in Nairobi, as well, when Kenya Airways officials barred him from getting on a plane for Uganda on Wednesday.
"We refused to allow him to board because our intelligence advised us that it would not be safe to do so," said Chris Karanja, a corporate affairs manager at Kenya Airways. He did not offer any additional details.
It was not immediately clear where the order to block Besigye from getting on the plane came from or why the action was taken.
Besigye said airline officials told him the plane would not be allowed to land In Entebbe, Uganda, with him on board.
Officials from Besigye's party, the Forum for Democratic Change, said the Ugandan minister of internal security denied that the government issued the directive.
"This is an example of the ongoing frustrations, concerns and violations of rights by the Uganda government," Besigye said.
"It is the right of every Ugandan to be able to return home at anytime. The government does not respect the rule of law."
Besigye has been thrown in jail several times for spearheading "walk-to-work" protests, contending that the government is manipulating prices for fuel and commodities.
Authorities in the east African nation had warned protesters that the gatherings are unlawful and participants will be prosecuted.
Museveni was elected to a fourth term as president in elections in February. Besigye was the leading opposition candidate in those polls.
Journalist Lillian Leposo contributed to this report.