If PV Narasimha Rao as home minister of the country had acted on the advice of former prime minister IK Gujral to call in the army at the earliest, the 1984 anti-Sikh massacre could have been avoided, Manmohan Singh said on Wednesday. The former prime minister was speaking at an event to mark the 100th birth anniversary of IK Gujral, who was India's prime minister in1997-98.