Protesters in Amritsar demanded the return of the armour and painting
Sikhs in India are protesting against the planned auction of some body armour at Sotheby's in London on 9 April.
They say the armour belonged to Guru Gobind Singh, the tenth and last religious head of the Sikhs.
The protests have been seen in the eastern city of Patna - birthplace of the Guru - and in Amritsar.
Prime Minister Manmohan Singh has been urged to try and stop the auction, and help get the armour housed in a Sikh museum at Amritsar's Golden Temple.
"This auction does not augur well," said Gyaan Iqbal Singh, the Chief Priest of Patna Sahib Gurudwara.
"So far," he said, "they have preserved our things and should try and return them at the earliest.
"We would even ask the Indian government and Prime Minister Manmohan Singh to try and get back the armour, as it is his duty as a Sikh as well as Prime Minister of the country."
There has been a series of protests over the sale of the armour over the past few days.
Guru Gobind Singh was one of the foremost military commanders, as well as a poet and spiritual leader.
He fought many battles with the Mughal emperors and their allies.