Indian authorities have tightened security at entry points and government buildings in the country's commercial capital Bombay, now officially known as Mumbai, after two car bombs killed at least 46 people yesterday.
More than 150 people were also injured when the bombs hidden in taxis went off in quick succession in the city's congested bullion market and the nearby plaza in front of the Gateway of India monument, the city's most famous attraction.
Hours after the explosions, police said they had found detonators on a rail line near Bombay that was to carry pilgrims to a Hindu festival.
No-one has claimed responsibility for the explosions that occurred seven minutes apart during the lunch-hour rush. But India's Deputy Prime Minister, Lal Krishna Advani, said the outlawed Students Islamic Movement of India (SIMI) "could" be behind the blasts. "Since last November, Bombay has been witnessing a number of attacks and in almost all the cases SIMI has been involved," Mr Advani said.
He said SIMI, which was banned two years ago, had been operating in conjunction with the Pakistan-backed Lashkar-e-Taiba militant group.
Witnesses yesterday said mangled cars, blood, body parts and shattered glass littered the area in front of the Gateway of India after the blast, which also damaged the windows of the nearby popular Taj Mahal luxury hotel.
Dazed survivors, many of them badly injured, ran for cover after the explosions, while scores of the injured were rushed to hospitals.
"It was a scene of complete anarchy and chaos. I knew when I lifted some of the injured that they had no chances of survival. They were dead," Mr Tanaji Pawar, a taxi-driver, said.
"The building we were in shook and we heard a loud noise," said Ms Ingrid Alva, a public relations consultant who works near the Gateway of India.
The city has suffered previous bombings this year. Twelve people were killed in March in a train blast during rush hour, and two were killed after an explosion aboard a bus four months later.
Yesterday's bombs went off hours after the release of a long-awaited archaeological report on a site in Ayodhya, north India, which is regarded as sacred by both Hindus and Muslims.
Sectarian rioting across India broke out after Hindu extremists demolished a mosque at Ayodhya in 1992. The dispute has also been linked to serial bombings in the port city a few months later in which over 350 people died.
India blamed Pakistan for those explosions.
Pakistan, however, was quick to condemn yesterday's attacks. "We deplore these attacks and sympathise with the victims and their families. Such wanton targeting of civilians should be condemned in the strongest possible terms," a foreign ministry spokesman said.