Police said many of the injured were in critical condition in hospital.
"This is a dastardly act and the guilty will not go unpunished," Prime Minister Manmohan Singh said of the attacks, the deadliest to hit India since 13 people died in a 2011 bombing outside the High Court in the capital New Delhi.
But Singh also appealed for "calm" in the aftermath of the Hyderabad blasts.
City police said there had been three explosions, but home minister Sushil Kumar Shinde said he could only confirm two.
At least 11 people were killed and 50 injured in two near simultaneous blasts in Hyderabad and the death toll could go up, Home Minister Sushilkumar Shinde said tonight.
Asked whether it was a terror attack, the minister said "it was too early to say anything and only an investigation will reveal it".
He said the two bombs were placed within a radius of 100 to 150 metres in Dilkhus nagar area in the Andhra Pradesh capital and placed in two bicycles.
"There were two blasts in Dilkhush nagar. I have spoken to the Chief Minister (Kiran Kumar Reddy) and he told me that the bombs were placed in two cycles and in one place eight people were killed and in other place three people were killed. 50 people were also injured," he told reporters here.
Asked whether the death told could go up, the Home Minister said "it is possible that death toll will rise".
He said authorities had received "intelligence inputs in the (recent) days about the possibility of attacks and this information was shared with other states".
Police said the blasts went off in quick succession.
Huge crowds gathered near the site of the explosions in the Hyderabad suburb of Dilsukh Nagar as police struggled to collect evidence.
"Ambulances have been rushed to the spot. Bodies have arrived and over 50 injured people have been brought to the spot," Kailash Nath, an officer at the Osmania General Hospital, said.
At the hospital, bloodied victims lay on stretchers as sobbing relatives pleaded for information about their loved ones.
Nath said that nine bodies had arrived at the hospital and 35 people were undergoing surgery.
The blasts came on the same day as Parliament opened for its key budget session, amid tensions following the hanging earlier this month of Afzal Guru.
PM says 'dastardly attack'
Prime Minister Manmohan Singh on Thursday decsribed the twin blasts in Hyderabad as an "dastardly attack" and said the guilty should not "go unpunished."
"This is a dastardly attack, the guilty will not go unpunished," a tweet from the Prime Minister's Office (PMO) quoted Manmohan Singh as saying of of the two blasts that killed at least 10 people and injured 50.
The PMO also said that the prime minister "strongly condemned" the bomb blasts.
"I appeal to the public to remain calm and maintain peace."
"PM also directed the central agencies to extend all possible help to Andhra Pradesh state authorities in relief operations," the tweet said.
BJP condoles loss of lives
BJP President Rajnath Singh on Thursday condoled the lost of lives in Hyderabad blasts and demanded that the government conduct a thorough probe into the incident.
"I express my condolences to the family members of those killed in the blast. This is a condemnable incident. I hope the government will take appropriate action to provide immediate and adequate relief to those injured in the blast," Singh said.
Singh also demanded that a thorough probe be ordered to find out the culprits and bring them to book.
He also said government should take steps to prevent recurrence of such incidents in future.
'NIA, NSG teams reached Hyderabad'
Elite teams of the National Investigation Agency (NIA) and the National Security Guard (NSG) will be flying to Hyderabad, which has been rocked by twin blasts that killed 10 people and injured 50, an official said.
"We have a news of two blasts. We have spoken to state chief secretary, DGP (director general of police) and governor (ESL Narasimhan)," home secretary RK Singh told reporters in New Delhi.
"Ten people have died and 50 have been injured in the blasts," he said.
He said the state police chief is reaching the blast site, which has been cordoned off.
"Our NIA team is also reaching as it has a hub there. The NIA officials are there at the site. Our IG NIA is also going from here. The post blast investigating team of NSG is also going," he told reporters,
The two teams will fly at 9.30 pm in a Border Security Force plane, he added.
The near-simultaneous blasts occurred near two theatres in Dilsukhnagar, a busy commercial area in the southern part of city, about 15 km from downtown.
Police have not yet confirmed either the cause of the explosions or the number of casualties.
The first blast occurred around 7 pm near a tiffin centre opposite Venkatadri Theatre and the second near Konark Theatre. Both the theatres are about 500 meters from each other.
High alert across Andhra Pradesh
Police sounded high alert in Hyderabad and other cities in Andhra Pradesh after two blasts killed over 10 people in Hyderabad and injured scores of others.
Police with dog squads began search operations in several busy market areas in Hyderabad and its twin city Secunderabad to foil any explosives.
Security was beefed up at Rajiv Gandhi International Airport at Shamshabad, state secretariat, Charminar and other vital installations, a police official said.
An alert was also sounded in coastal city of Visakhapatnam, temple town of Tirupati and other major towns across the state.
With inputs from PTI, AFP, IANS)
People search for survivors of bomb blast at Dilsukhnagar in Hyderabad. PTI photo
