Police arrested a man on Monday over Sunday's attacks at Bodh Gaya's Buddhist temple and were studying CCTV footage that appeared to show two men planting explosives at the site.
The government condemned the "terror attack" at one of Buddhism's holiest sites after nine small bombs exploded on Sunday morning, wounding two monks at the world-renowned pilgrimage destination in eastern Bihar state.
"The police are doing everything to identify the two persons on the basis of the CCTV footage," Gaya superintendent of police Chandan Kushwaha told AFP.
"We have found a few things in his possession but it will be premature to describe him as a terrorist. His father, Bhajju Mistri, has a Naxal background and we are looking for him," he said.
"All the CCTV cameras at the temple premises were fully functional. As evident in the CCTV footage, both the state security personnel and temple's own security staff was present. There was no lapse on the security front."
No one has claimed responsibility for the attack, but police arrested a local man who was being questioned in connection with the blasts.
"A man identified as Vinod Mistri was taken into custody in connection with the serial bomb blasts in Bodh Gaya," state police official SK Bharadwaj told AFP.
Police picked up Mistri in the Barachatti area, a stronghold of Maoist insurgents 129 kilometres (80 miles) south of the state capital Patna, Bharadwaj said.
According to the DIG, Magadh range, Nayyer Hasnain Khan, the man has been detained based on an identity card found in the temple complex on Sunday after the blasts. The suspect is being questioned by the NIA.
He also said that there was no security lapse on part of the police.
Delhi police said they had earlier warned officials that Islamic militants could target the temple complex as revenge for Buddhist violence against Muslims in neighbouring Myanmar.
Attacks on Buddhists are rare in the country, but there have been tensions in the region recently following clashes between Buddhists and Muslims in Myanmar, as well as in Sri Lanka and Bangladesh.
Two more bombs were found and defused at the complex on Sunday, one of them near the temple's celebrated 80-feet-tall (24-metre) statue of the Buddha.
Along with temples, dozens of monasteries housing monks from around the world are located near the complex, which is believed to contain the holy bodhi tree under which the Buddha reached enlightenment in 531 BC.
After his meditations beneath the tree, the Buddha is said to have devoted the rest of his life to teaching.
The Bodh Gaya complex also houses multiple shrines marking the places where the Buddha is believed to have spent time after his enlightenment. He founded an order of monks before dying aged 80.
The complex, a UNESCO World Heritage site 110 kilometres south of Patna, is one of the earliest Buddhist temples still standing in India.
Tibetan spiritual leader the Dalai Lama makes frequent trips to the complex, which attracts visitors during the peak tourist season from October to March.
(With HT, PTI and AFP inputs)