The arrest and detention of at least 18 people from across the country by the National Investigation Agency and the Delhi Police over the last few days for their alleged terror plans and sympathies to the Islamic State is a stark warning that the authorities need to be on heightened alert.

The Delhi Police caught four young men from Uttarakhand, while the rest have been arrested by the NIA from across India. Both groups are accused of planning to carry out major terrorist attacks. Read more