Lusaka - Zambian police on Monday used batons and teargas on a crowd of opposition activists gathered outside a police station in the capital where their leader had been summoned, an AFP reporter witnessed.
Hundreds of people turned out to support Hakainde Hichilema, who leads Zambia's third largest opposition party, as he arrived at the police station to face a charge of spreading false information.
Hichilema, leader of the United Party for National Development (UPND), is accused of making false allegations that militia were attempting to harm opposition politician, Frank Bwalya.
Bwalya was charged with defamation last week after he compared the president to a potato.
Hichilema's supporters said they feared he could be poisoned while in police custody and were there to provide protection.
“I came to give support to my president. The police acted unprofessionally by teargassing our leader, and they have beaten me badly,” said one, Munji Habenzu, limping from the injury.
“This is total rubbish and Zambians should wake up and not allow this to continue.”
A journalist from the privately owned broadcaster Prime Television and a lawmaker from Hichilema's party were among the injured.
Hichilema decried what he called the “brutal Sata state” - a reference to Zambia's President Michael Sata.
Police, however, defended the use of force.
“There is no way we could have handled them with care, one of our officers was also attacked,” said police spokeswoman Charity Munganga Chanda.
Hichilema was interrogated and given a formal warning before being released.
“We have recorded a ...statement for the offence of publication of false news with intent to cause fear and alarm,” said Chanda.
He could still be arrested when police have completed investigations, his lawyer Sakwiba Sikota said.
It is not the first time Hichilema has been in trouble with authorities. In 2012 he was arrested on similar charges after claiming that the ruling Patriotic Front was planning to send young people to Sudan to train as militias.
Sata's government came to power 2011 and has come under fire for its treatment of opposition figures.
Several opposition leaders including the country's former president Rupiah Banda are facing criminal charges.