Why weren't they ready for this?

This is a photo of some Indian police standing guard outside India's largest mosque, the Jama Masjid, in New Delhi. Two bomb blasts have gone off in this mosque after Friday prayers, injuring 14 people.

The police have nabbed four suspects and are looking for more. No details are made as to who and why the bombs were triggered.

Now security has been stepped up at temples and mosques across northern India to guard against reprisal attacks.

But can’t this itself be a reprisal attack following the bomb blasts in the Hindu holy city of Varanasi a month ago which killed 23 people?

If the troops had been one high alert since then, these blasts may have been evaded.