NEW DELHI/ISLAMABAD, 16 May — India yesterday vowed to avenge the killing of 31 people in an attack by three armed men in southern Kashmir on Tuesday. “We will have to retaliate,” Prime Minister Atal Behari Vajpayee told Parliament, describing the attack near Jammu, the summer capital of the northern Jammu and Kashmir state, as “a massacre of innocents”.

Vajpayee did not say what form the action could take or who it would be directed against, and the Hindi word he used has a wide range of dictionary meanings, including revenge and counteraction.

Defense Minister George Fernandes, visiting the site of the attack, also called for retaliation. “... it is a situation which calls for punishment,” he said. “What that punishment will be is something that needs to be deliberated upon but we cannot certainly have this kind of terror go unpunished.” India’s archrival Pakistan, blamed by Indian leaders for the attack, has condemned it and urged an investigation.

Twelve secessionists were killed, meanwhile, in a string of clashes between activists and security forces in Indian-administered Kashmir over the previous 24 hours, authorities said. India and Pakistan have massed a million men along their border since December in a confrontation over the Himalayan region. Police in Pakistan-administered Kashmir said one person was killed and another injured when Indian troops fired shells into southern Rawalakot district. They said a 16-year-old boy was killed and a five-year-old child wounded in the village of Battal. Police did not say if Pakistani troops had returned fire.

India’s junior home minister, I.D. Swami, said Indian troops would remain on the border with Pakistan until New Delhi was convinced that Pakistan had stopped stoking the rebellion in Kashmir.

US Assistant Secretary of State for South Asia Christina Rocca, in New Delhi on her third round of shuttle diplomacy since March, said the raid by the gunmen was aimed at sabotaging efforts to ease tensions between India and Pakistan over Kashmir.

“We certainly think that the level of tension needs to be eased somehow and acts like this are clearly aimed at achieving the opposite objective...,” she said before flying to Islamabad.

In Pakistan, she said the two countries could reduce the tension only through negotiations. “Our position is nothing can be resolved without dialogue,” Rocca said at a press conference following talks with Pakistan President General Pervez Musharraf in Islamabad. Vajpayee’s comment and the upturn in tensions rattled Indian financial markets, sending bonds and the rupee down.