Attacks on religious institutions, resulting in the death of innocent devotees, is perhaps one of the worst forms of irony.
As investigations are on in the US gurudwara shooting, in which seven people died and three were critically hurt, we look at some other incidents where religious places have been under fire.
The attack on the Akshardham Temple in Gujarat occurred on 24 September, 2002. Two gunmen opened fire at about 4.30 pm when nearly 600 devotees were in the temple premises.
The National Security Guard commandos were summoned. The operation lasted for almost two hours at the end of which 29 people were killed and 79 injured.
Chabad House in Mumbai was one of the targets of the 26/11 terrorists. It had an educational center, a synagogue and also a hostel.
The building was attacked and six of its occupants, including Rabbi Gavriel Noach Holtzberg and his wife Rivka, who was five months pregnant, were killed during the November 2008 Mumbai attacks.
Their two-year-old son Moshe survived the attack after being rescued by his Indian nanny, Sandra Samuel.
Mosques in Africa
On 13 July, 2012, a suicide bomber blew himself up outside a mosque in Nigeria's Potiskum town. Five people are reported to have died and six injured in the attack.
The target of the attack was said to be Muhammad Abali, the top Muslim traditional leader in Yobe state.
On 2 July, 2012, Islamists smashed the wooden doors of an old mosque in Mali. This was one in a series of attacks on reiligious momuments which even drew condemnation from the United Nations.