The public order teams of Britain's Metropolitan Police Service will be armed with taser stun guns from Monday in response to an upsurge in extreme violence, Sky News reported.
Around 400 Territorial Support Group officers have now been trained to use them.
The country's biggest police force has promised to use taser stun guns responsibly, which have been issued for wider use across London.
The weapons stun their targets with 50,000 volts. Owing to safety concerns, the Metropolitan Police Authority initially resisted moves to join the nationwide taser pilot programme.
Bob Broadhurst, the commander in charge of London's public order teams, said the decision to participate now had been partly driven by an upsurge in extreme violence in the city.
The decision to give the weapons to some non-firearms officers was, he said, "an appropriate response to the rise in violence against front line officers and members of the public."
In the past, only highly trained firearms officers were allowed to carry the stun guns.
Broadhurst noted that the weapons would be used only in situations where there is a real risk of violence.