By the side of a narrow road in suburban Mumbai is the Maharashtra Forensics Laboratory.

It is a building like any other government establishment -- constables sit at a table at the entrance, watching over a visitors' register as they direct visitors to different offices in the building.

In one of the offices sits Dr Rukmani Krishnamurthy, director of the lab.

Her office door is flanked by two well-potted plants, her name written in Hindi on a blackboard. Inside, her chair is placed under framed pictures of B R Ambedkar, Chhatrapati Shivaji Maharaj, Mahatma Gandhi and Jawaharlal Nehru.

Dr Krishnamurthy and her 10-member team have had a hectic schedule since the week began.

The Mumbai blasts at the Gateway of India and Zaveri Bazar, she says, has seen her team working 16 to 18 hours a day to investigate and submit the forensic report of the explosions.

"I have been so busy today. We have to continue with the investigation and I have to deal with the media," she says, taking off her glasses.

Surprised to know that the lab's report that RDX was the explosive used in the blasts was already known, she quickly reaches out for an afternoon newspaper to see if the report has been featured yet.

Looking over the ID pinned on her shoulder to scan the tabloid, she says the lab sent four members to each blast site.

"Our experts carried out a meticulous search for 3 to 4 hours," she added.

The forensic investigation, she says, began on Monday evening itself. Making it plain that she would not go into the specifics of the composition of the bomb, she said it was enough to know RDX caused the blasts.

"At this stage, it is not right to go into such details. We should not encourage it," she says.

Comparing the August 25 blasts to the previous blast in a BEST bus in Ghatkopar, Dr Krishnamurthy revealed that while gelatin was used in the BEST bus explosion, the combination of RDX with the CNG cylinder -- used as fuel by the taxis involved in Monday's blasts -- magnified the intensity of the explosions this time.

The explosions created a crater at both sites, which is attributed to the CNG factor.

In simple terms, an explosion is when a substance burns very quickly, producing a lot of gas and heat at rapid speed.

"The wind flows at very high speed and temperature and causes great destruction. The pieces of vehicles hit the bodies causing death and damage," explains Dr Krishnamurthy.

RDX or Research Development Explosive, a white powder, is mostly used for military purposes. It is also called C-4 and can be easily moulded. It is hard to set off without a detonating device and is relatively insensitive to friction.

C-4 was used by Al Qaeda terrorists in their attack on the USS Cole that killed 17 American sailors in Yemen in October 2000.

It is not known what quantity of RDX was used in the Mumbai blasts. Dr Krishnamurthy says it is difficult to ascertain it. The full investigation is likely to take another week.

With five blasts in recent months in Mumbai, she has been at the centre of the investigations since she took over as the lab's director a year ago.

"The scientific evidence is a foolproof tool for the criminal justice system," she adds.

A member of the city's disaster management group, she says her department, overworked and short-staffed as it may be, is capable of providing tatkal [immediate] service in emergencies like these.

Of the 659 staff allotted to the lab, 138 vacant posts need to be filled up.

The lab will also conduct DNA tests on unidentified body parts. The number of cases will be known Thursday, August 28, after a meeting with doctors at the J J Hospital, one of the three hospitals where the blast victims were taken to.

As Mumbai is targeted by the terrorists' diabolic designs, the demands of Dr Krishnamurthy's job get tougher. But she is confident of the expertise of her staff and her lab -- the oldest in the country which she joined in 1974 -- and assures us that it has state-of-the-art equipment.

"Our findings of the 1993 blast were same as Interpol's," she says.