Anti-tax protesters in Kenya are in shock after a 29-year-old man was killed during nationwide demonstrations against a new finance bill.

Rex Kanyike Masai died of gunshot wounds, a doctor from a hospital in the capital, Nairobi, has told a local newspaper.

Police fired tear gas and water cannon at largely peaceful protesters near parliament as lawmakers were debating proposals to bring in new taxes.

Amnesty International has accused the police of using excessive force to contain protesters, saying than 100 people were arrested on Thursday.

When the protests, dubbed "Occupy Parliament", began on Tuesday, the public outcry forced the government to withdraw some of contentious provisions, including a 16% tax on bread and an annual 2.5% tax on vehicles.

But it has not stemmed the anger of the mainly youthful protesters, their ire focussed on the government of President William Ruto.

Since becoming president, he has introduced several new and unpopular taxes, which critics say stifle economic growth and lead to job losses.

The police say they have visited the scene of the shooting and are investigating the circumstances of Mr Masai’s death.

Activist Boniface Mwangi has said the young man was only carrying a national identity card and his phone and had not been armed.

His mother, Gillian Munyao, told Citizen TV that her son had been coming back from work when he was shot in the city centre.

"He was evading tear gas when he was shot," Ms Munyao said.

He was taken to Bliss Hospital along Nairobi's Moi Avenue where he was pronounced dead, officials there said.

“He was shot in the upper middle part of the thigh. It appears he bled to death before being brought to our facility,” the doctor told Kenya’s Nation news website.

Kenyans have taken to social media to mourn and demand justice for the young man.

"We will print posters with Rex’s face and name around Nairobi terming him as a hero. We will cover the burial expenses as well," Hanifa Farsafi, reportedly one of the protests' organisers, posted on X, formerly Twitter.

"My heart is absolutely broken... but it was not in vain," she added.

A total of 39 people were injured during Thursday's protests, with eight among them in critical condition, according to Kenya Red Cross.

Those in critical condition have been evacuated to Kenyatta National Hospital, the country's biggest referral hospital, for further treatment.

Amnesty International alleged some police officers had been using fire arms.

"There is confirmation of live shootings verified by the presence of spent cartridges," the rights group said.

The victims suffered wounds ranging from “soft tissue injuries and inhalation of tear gas”, it added.

Faith Odhiambo, the Law Society of Kenya (LSK) president, condemned police "brutality" and the "illegal" arrest of protesters.

Police are yet to comment on the accusations.

But in an earlier statement, police chief Japhet Koome had said protesters would not be permitted to access critical government infrastructure or disrupt parliamentary proceedings.

Despite the protests, the controversial bill was passed by a majority of MPs during its second reading on Thursday.

It will now go on to the next stage where a committee will consider amendments - and the final vote is expected next Tuesday.

The protesters want MPs to reject the entire bill.

The government has often defended the tax measures as necessary to reduce the country’s national debt of nearly $80bn (£63bn).