this is the face of policing in London in the age of Islamic terrorism

Two armed officers pictured patrolling Horse Guards Parade earlier today 

Both were armed with Heckler and Kocch powerful semi-automatic rifles

Were also carring Glock 17 9mm pistols as well as a taser guns 

Security at tourist hotspots across the city has been boosted recently

Comes after unarmed guard was shot dead at Canada's War Memorial 

Westminster is also on high alert in case of a terrorist attack on Parliament