Thousands protested in Punjab on Monday, torching a train, vehicles and shops after a Sikh preacher was killed on Sunday in an attack on a temple in Austria's capital Vienna, police said. Authorities imposed a curfew on parts of the state and the army was put on standby after members mainly of the Dalit or “untouchable” community protested against the attack in Vienna that killed one of their leaders, according to police. “The situation remains tense but under control,” said senior superintendent of police R.K Jaiswal, from Jalandhar in Punjab where the violence was centered. At least 16 people were wounded on Sunday when six armed men attacked two preachers visiting from India with a gun and knives during a ceremony in a Vienna temple. Guru Sant Rama Nand, 57, died in the night after an emergency operation, police said. The second, Guru Sant Niranjan Dass, 68, is in a stable condition. Both had suffered bullet wounds. Four of the attackers were severely wounded, two of them life-threatening, when they were overpowered by worshippers. The other two were only lightly wounded and are in police detention. At least some attackers were residents and had previously asked for asylum in Austria, prosecutors said. Around 2,800 Sikhs lived in Austria in 2001, according to the last census. Austrian news agency APA quoted temple officials as saying members of rival temples had threatened violence if he appeared. Police denied it had been warned of a possible attack. The Guru who died was said to be from the Dera Sach Khand, a religious sect which draws large support from the Dalit community and is considered separate from mainstream Sikhism. Sikhism officially rejects caste but social hierarchies still prevail in the state, and followers who protested from the Dera Sach Khand identified themselves as from the Dalit caste. Activists from a powerful political party, which draws its support mainly from Dalits, the Bahujan Samaj Party (BSP), have joined the protests. Indian Prime Minister Manmohan Singh called upon people in Punjab to “maintain peace and harmony”: “Invoking the teachings of the Gurus, I appeal to all sections of the people in Punjab to abjure violence and maintain peace,” he said in a statement.