Two powerful near simultaneous blasts rocked Hyderabad on Thursday killing at least 16 people and injuring 119 others.
"Saw friend / foreign secretary Mathai- discussed importance of relationship w/ #India, expressed sympathies to brave people of #Hyderabad -JK," Kerry said in his first tweet as the top American diplomat.
Kerry used the usual state department twitter handle but signed it off with his initial JK (meaning John Kerry), which State Department officials said means was his "personal tweet".
Earlier, the US State Department also condemned the terrorist bombings and offered assistance in investigation if requested by the Indian Government.
"We condemn the cowardly attack in Hyderabad, India, in the strongest possible terms, and we extend our deepest sympathies to those affected and to the people of India," state department spokesperson Victoria Nuland told reporters.
"The US stands with India in combating the scourge of terrorism, and is also prepared to offer any and all assistance that Indian authorities may need," Nuland said.