Five people were arrested on Thursday after a third blast in less than a week shook the area around the Sikh holy site of the Golden Temple in Amritsar, Indian police said.
Two of the suspects had prepared the improvised explosive devices at a guest house in the city, state police director general Gaurav Yadav told reporters, while the other three provided the materials.
He gave no information about their suspected motives and said investigations were continuing.
Pressure for a separate Sikh homeland known as Khalistan sparked deadly violence in India in the 1980s and 1990s.
In March, a manhunt was launched in Punjab state to arrest a firebrand Sikh separatist that sparked protests and vandalism among the diaspora.
It was unclear whether that was connected to the three explosions.
No injuries were reported in the third blast, which happened around midnight, with police describing it as low-intensity.
“The area is totally sealed and a forensic team is working on it,” police official Naunihal Singh said.
The previous two blasts, at the weekend and on Monday, each wounded one person.
Punjab’s Golden Temple, a gleaming edifice in a large artificial pond, is revered by Sikhs the world over.
But it has been the scene of violence in the past, most notably when Indian special forces stormed it in 1984 to remove Sikh militants.
