ISLAMABAD, Feb 7 (Reuters) - Thousands of mourners gathered in Islamabad on Saturday to start burying the 31 people killed in a suicide bombing at a Shi'ite Muslim mosque during Friday prayers, as the city tightened security due to concerns there could be further attacks.
In Friday's attack a man opened fire at the Khadija Tul Kubra Imambargah compound on the outskirts of Pakistan's capital, then detonated a bomb that killed 31 people, as well as himself, and injured more than 170.
