India Home Minister Shinde visits Hyderabad blast site
India's Home Minister Sushil Kumar Shinde has visited the sites of two blasts in the city of Hyderabad in which 16 people were killed.
Mr Shinde said Thursday's bombs had been planted on bicycles 150m (500ft) apart near a crowded fruit market.
No group has yet said it carried out the attack, which also left 117 people injured.
Major Indian cities are on alert as police investigating the blasts have detained a man for questioning.
On Friday, Mr Shinde visited the sites of the blast in the Dilsukhnagar area, a busy commercial and education hub, as well as visiting some of the injured in hospital.
Asked who he thought could be behind the blasts, Mr Shinde said: "At this moment we cannot say anything. The matter is under investigation."
On Thursday Mr Shinde told reporters in Delhi that authorities had received intelligence about possible attacks in the country but no specific information as to where or when they might occur.
The explosions hit the busy Dilsukhnagar neighbourhood, which is crowded with cinemas, shops, restaurants and one of India's largest fruit and vegetable markets.
Senior police officer V Dinesh Reddy told the Associated Press news agency that improvised explosive devices had been used.
Prime Minister Manmohan Singh called the explosions a "dastardly attack" and said the "guilty will not go unpunished".
Mumbai and the rest of Maharashtra state have been put on high alert following the blasts, with measures such as increased police presence on the streets and random vehicle searches.
Meanwhile, Australia's cricket team says it has held talks with Indian authorities about its players' safety in the wake of the bombings. The second Test of the India-Australia series is due to start in Hyderabad on 2 March.
The blast is the first major attack in India since a September 2011 bombing outside Delhi's High Court killed 13 people.
There have been at least nine attacks on the city since 1992, including twin explosions in 2007 that killed more than 40 people.
The city has a sizeable Muslim minority, is a stronghold of the Muslim political party, MIM, and has a long history of religious tension, says the BBC's Soutik Biswas in Delhi.
He says religious tensions grew from the 1980s and 1990s with Hindus and Muslims moving out of mixed areas into community ghettos.