A cartoon on Dalit icon BR Ambedkar in an NCERT textbook rocked parliament yesterday, prompting the government to apologise and order the removal of the “objectionable” sketch. After Opposition leaders created an uproar over the cartoon which they said was insulting, Human Resource Development Minister Kapil Sibal said he was not personally responsible for the row but had “no hesitation in apologising to the nation”.He said a committee of the HRD Ministry was already reviewing all such “objectionable matters in textbooks”. Reacting to BSP chief and Dalit leader Mayawati’s demand for a time frame for action, Sibal said that Ambedkar was “not the property of any one segment”.