WITH INDIA in the grip of a wave of terrorist attacks that have claimed more than 200 lives already this year, it was only a question of when, rather than if, Mumbai would be hit.
Despite claims by India's security forces to have rounded up many of those involved in the bombings that struck Delhi in September, there appeared to be little national confidence that the killings were at an end.
It was only on Sunday that the Indian prime minister Manmohan Singh, announcing the formation of a taskforce to tackle terrorism, warned of the scale of the threat facing the country.
"I only wish to emphasise here that time is not on our side," he said. "We cannot afford a repetition of the kind of terrorist attacks that have recently taken place in Delhi, Hyderabad, Bangalore, Mumbai, Ahmedabad, Surat, Guwahati and some other urban centres."
Although yesterday's killings involved gunmen rather than bombs, the degree of co-ordination involved points to the same hand at work.
The most obvious suspect will be a group calling itself the Indian Mujahideen, an offshoot of the banned Students' Islamic Movement of India (Simi). It claimed responsibility for the bombings in Delhi, Bangalore, Jaipur and Ahmedabad, and after the Delhi bombings it threatened that Mumbai would be next.
In an e-mail it accused the city's anti-terrorism squad of harassing Muslims. "You should know that your acts are not at all left unnoticed; rather we are closely keeping an eye on you and just waiting for the proper time to execute your bloodshed," it said. "You are already on our hit list and this time very, very seriously."
One name that will be at the forefront of the investigators' minds is that of Abdul Subhan Qureshi, also known as Tauqeer, a Mumbai-educated member of the Indian Mujahideen credited with masterminding several attacks.
His name also cropped up in an investigation into bombings in Assam, with intelligence agencies claiming to have intercepted several congratulatory e-mails. He first came to the attention of the authorities after the train bombings in Mumbai in 2006 and was suspected of involvement in the Ahmedabad and Delhi attacks.
Figures from India's home ministry show that there have been 64 bomb attacks in six months, killing more than 215 people and injuring 900.
Mumbai has been a regular target for terrorists since 1993, with six major attacks since then.
In July 2006 200 people were killed and more than 700 injured in seven bomb attacks on the city's Western Railway line. In August 2003 46 people died in two explosions and in March 2003 bomb blasts killed 257 people and injured about 700. In that attack the terrorists also targeted hotels, along with the Bombay stock exchange, theatres, and a number of other sites.
After other recent attacks, security sources suggested that Pakistan and Bangladesh had assisted the bombers and it seems likely that investigators will again look at possible links with those countries to the latest attacks.
Following the Delhi bombs in September Muslims protested in the capital, blaming Simi and demanding that Pakistan abstain from involvement in terrorism in India. The Indian authorities have acknowledged that the country has its own home-grown terrorist problem