Government doesn't say how 18-year-old died in hospital, but an opposition leader claims cause of death was torture.
Bahrain authorities say a detainee has died after being taken into custody during clashes between security forces and
The government on Thursday issued a statement saying that public prosecutors are investigating the death.
The brief statement gave no further details on the death, but said the detainee was hospitalised and accused of "vandalism" during widespread demonstrations on Wednesday.
"He died in hospital and the public prosecution has been notified," it said.
Leading opposition figure Matar Matar told the AFP news agency that Mohammed Yaaqub, 18, was chased by police vehicles and that his body "was stuck between two [police] cars that were following him".
"Instead of receiving the necessary medical treatment, the police took him to the yard opposite Sitra police station where he was tortured," said Matar, a former MP.
The interior ministry said 41 officers were injured in "orchestrated attacks on police" on Tuesday, as tensions rise almost a year after the eruption of Shia-led democracy protests that were crushed last March.
Ebahim told the Lebanese al-Akhbar newspaper that, "the new policy is trying to minimise torture inside prisons, but the alternative is that they torture in other places, such as construction sites".
In a statement released Thursday, the London-based advocacy group Amnesty International warned that the use of tear-gas against protesters had become "increasingly deadly".
It called on the Bahraini government to investigate "the more than a dozen" tear-gas related deaths since February 2011.
"The rise in fatalities and eyewitness accounts suggest that tear gas is being used inappropriately by Bahraini security forces, including in people's homes and other confined spaces," said Amnesty.
About 40 people have died in nearly a year of nonstop unrest between Bahrain's Sunni monarchy and the island kingdom's majority Shias seeking a greater voice in government and security affairs.