NEW DELHI/BALLABHGARH: A baby and a toddler were killed in a house fire allegedly set by their family’s upper caste neighbors, and hundreds of angry residents placed the children’s bodies on a key highway near the Indian capital to demand the attackers be arrested.

The 2½-year-old and 9-month old were sleeping when the attackers poured gasoline and set the fire in Sunpedh village Monday night. The children died while their mother was in critical condition, police said. The father was injured as he tried to break down the locked door of the house. Four men have been arrested.

The attack will feed concerns over rising intolerance after the rumour-fuelled killing of a Muslim man by a Hindu mob recently.

Rahul Gandhi, leader of the opposition Congress party, visited the district and criticized federal and state officials for not making better efforts to protect poor people. Caste-related violence has gripped India for decades.

Federal Home Minister Rajnath Singh described the attack as “very unfortunate and condemnable.” He spoke to the chief minister of Haryana state where the village is located, to ask for immediate steps to restore calm.

Police said there was long-standing enmity between the castes since three upper caste men were killed last year.

India has a long history of such incidents. Though caste discrimination was outlawed soon after India’s independence from Britain in 1947, it persists in Indian society. Disputes between different castes are a common cause of violence.

On Wednesday, two men carried the bodies of the dead children wrapped in white shrouds during a protest by about 1,000 people who blocked a major highway to the northern city of Agra, home to the Taj Mahal monument, and argued with police.

Police in the northern state of Haryana said a group of men killed the children, a girl of 8 months and her two-year-old brother, by setting alight gasoline poured through the windows of their home in Ballabhgarh district, about 50 km (31 miles) from the capital, New Delhi.