Prime Minister Manmohan Singh and Congress president Sonia Gandhi addressed a rally in Kashmir on Tuesday, a day after heavily-armed militants killed eight soldiers in the deadliest attack in Srinagar for five years.
Singh was to be accompanied by Sonia Gandhi for a two-day visit in which he will inspect major infrastructure projects and inaugurate part of a railway line to connect north and south Kashmir.
More than a dozen armed rebel groups have been fighting Indian forces since 1989 for Kashmir's independence or its merger with Pakistan and tens of thousands of people, mostly civilians have died in the fighting.
Mohammed Afzal Guru's execution, carried out in Delhi's Tihar Jail without first informing his family, triggered widespread protests in Kashmir where many doubted his guilt.
Much of Kashmir has since been put under curfew repeatedly while protests and strikes have disrupted daily life.
Police and paramilitary forces have been deployed in strength across the region ahead of Singh's visit, with additional check points along major highways.
Eight soldiers were killed and 13 others were wounded, a police official said on condition of anonymity.
The militants, travelling by motorbike, opened fire on the army vehicles which were en route to a nearby base, before lobbing a grenade at one of them, police sources said.
Hizbul Mujahideen, a local pro-Pakistan militant, group claimed responsibility.
The three main separatist groups have called for a strike on Tuesday to protest against Singh's visit.
"This is a protest against the forcible military occupation of Kashmir and we want to give the Indian prime minister this message that by hanging Afzal Guru, New Delhi has sent the entire Kashmiri people to the cross," Syed Ali Geelani, a top separatist leader, said in a statement.
Officials say a few dozen youths have been detained in police stations to "prevent protests" during the visit, although separatist leaders put the figure at hundreds.
It was the deadliest attack on security forces since July 2008 when a landmine killed nine soldiers on a bus on the outskirts of Srinagar.
Chief minister Omar Abdullah was among those who condemned Monday's attack, saying it was "aimed at restoring the shattered morale of the militants".
Abdullah is an ally of Singh but has criticised the Delhi government for showing what he regards as a lack of political will to resolve the underlying tensions here.
"The Kashmir issue needs to be addressed politically. Economic packages are not a solution to the issue nor can it be found on the point of a gun," Abdullah said recently.
In an editorial on the eve of the visit, the local Kashmir Reader daily said the security measures put in place during the visit "only proves to be a reminder of broken promises".
Singh is expected to review a federally funded reconstruction package he had announced nine years back after taking office for his first term.
He will also inaugurate part of an ambitious project expected to link the landlocked Kashmir valley with the massive Indian railway network by 2018.
During a visit in 2009, Singh inaugurated another section of the rail link and also reiterated his commitment to an economic reconstruction package worth around $4 billion.
Officials in the local government say only about only 40% of the allocated resources have been used so far.