At least one person has been killed and 22 wounded after violence broke out at an Ethiopian Christian festival.
Wubishet Solomon said he had no idea why he was shot in the neck
Some of the tens of thousands of people started chanting opposition slogans and throwing stones, police say. They responded with live bullets.
There been several violent opposition protests in the capital, Addis Ababa, since last May's disputed elections.
On Thursday, the UK suspended direct aid to the government over concerns about its commitment to human rights.
'Breach of trust'
A civilian was killed when a protester threw a hand grenade at the authorities, police say.
But some witnesses say the police over-reacted.
"I don't really know what was happening to me. I was shot by the police twice, one on my stomach and one on my throat," Wubishet Solomon, 16, told the AP news agency.
Many of the country's opposition leaders are now in jail
He said he was listening to religious music when the shooting started.
To mark the Timkat festival, tens of thousands of Ethiopian Orthodox Christians march through the streets carrying replicas of the Ark of the Covenant, which they believe is kept safe in northern Ethiopia, reports the AP news agency.
During a visit to Ethiopia this week, UK Development Minister Hilary Benn said all British aid to the country would now be earmarked for specific projects.
Ethiopia Prime Minister Meles Zenawi was once seen as a key British ally and was a member of the British prime minister's Commission for Africa.
Mr Benn said there had been a "breach of trust" since more than 80 people were killed in opposition protests last year.
Some 100 opposition leaders, journalists and aid workers remain in prison on charges ranging from treason to "genocide" in connection with the unrest.
Last May's polls were the most closely contested in Ethiopian history, and resulted in the opposition winning more than 100 seats in parliament.
But the opposition believed they had been cheated of victory, and took to the streets.
The clashes left many dead, and Mr Meles accused the opposition of attempting to overthrow his government.
Western governments tried to bring the parties together, but with limited success.
Until last year's elections, Mr Meles had been praised for opening up political debate and for liberalising the economy.