Investigators got their first breakthrough in Hyderabad's Mecca Masjid blast with the recovery of a SIM card from a mobile phone connected to one of the unexploded bombs in the mosque premises, an official source said on Saturday.

A bomb disposal squad had recovered a SIM card from a mobile phone attached to an unexploded Improvised Explosive Devices from the blast-hit mosque premises, a source from the Andhra Pradesh Forensic Science Laboratory said.

"The defused bombs were attached to a Nokia mobile and we have started tracing the person with the help of the SIM card," the source said.

A blast rattled the mosque when devotees were offering their Friday afternoon prayers at the historic Mecca Masjid on Friday, leaving 14 people dead, including some killed in police firing during subsequent protests.

Three live bombs were detected at the mosque in the communally-sensitive Charminar area and defused -- two soon after the blast at 1.30 pm in an area where ablutions are performed and the third later in the evening near the gate.