Indian Prime Minister Manmohan Singh will on Sunday visit the southern city of Hyderabad after twin bombings this week that killed 16 people and injured 117, an aide said.
Singh will arrive in the morning and is expected to visit hospitals where the injured are being treated and meet local political leaders, the aide to the prime minister, who declined to be named, told AFP late Saturday.
The premier has vowed to bring to justice the perpetrators of the "dastardly" attack, which saw two bicycle bombs explode within a few minutes outside a cinema and a bus stand on Thursday evening in the Dilsukh Nagar district .
They were the first deadly bombings in India since 2011 and triggered international condemnation including from rival Pakistan.
The government was strongly criticised on Friday in parliament by the opposition which said the bombings had exposed systemic security failures at a time when India is on heightened alert.
The attacks also raised questions about whether Australia's cricket team would go ahead with a scheduled match against India in Hyderabad starting on March 2, although organisers said the city would still host the Test.
As investigators sifted through wreckage Saturday in their hunt for the perpetrators, Andhra Pradesh state Home Minister P. Sabita Indra Reddy said "vital clues" had been found, but did not give any details.
"We are confident we will crack the case soon," said the minister, according to the Press Trust of India.
Newspapers have pointed the finger at the Indian Mujahideen -- a banned militant outfit which has claimed responsibility for previous attacks.
The fitting of the explosive devices to bicycles was similar to tactics used in other attacks by the Indian Mujahideen, local media reports quoted investigators as saying.
The homegrown group has links to Lashkar-e-Taiba, the Pakistan-based militant outfit blamed for the 2008 Mumbai attack that claimed 166 lives, according to Indian intelligence officials.
New Delhi has long accused its neighbour of aiding and abetting the militant groups who have carried out attacks on Indian soil -- a charge that Pakistan rejects.