Suspecting the hand of a woman in the July 28 Ghatkopar bomb blast in which four persons were killed and 47 injured, police sources said on Saturday.
"We are trying to establish her identity and her role in the blast," police sources said.
Militant outfits are known to keep changing their modus operandi to achieve their objectives and "the use of women to carry out blasts cannot be ruled out," they said.
Police teams have been sent outside Mumbai too to search for clues, they added.
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