( CNN ) -- Police have added a second charge of capital murder against an Irving , Texas , woman who allegedly told a 911 operator that she strangled her two young children because they were autistic , a spokeswoman for the district attorney said Friday . Saiqa Akhter , 30 , now faces two charges of capital murder of a child under 5 in the deaths of her 2-year-old daughter and 5-year-old son , Dallas County district attorney spokeswoman Jamille Bradfield said . A woman who identified herself as Akhter called police Monday evening and said she first tried to kill her children with bathroom cleaner , but they would not drink it . She told the 911 operator that she then strangled them with a wire and that they were on her bed . Police and paramedics tried to resuscitate the children , but Zain Akhter died at the hospital Monday , and his younger sister , Faryaal Akhter , died at the hospital Tuesday evening , according to authorities . On the tape , the woman tells the operator , `` I killed them . I killed both of them . I killed my both kids . ... They are not doing anything . They are just blue . They are not taking any breaths . Their heart is not beating . '' The operator asks her what happened . `` First , I tried to give them bathroom cleaner . I put in their mouth , but they do n't drink it . I want them to drink it . They do n't drink it . ... I grabbed their neck ... and they are no more , '' she says on the tape . The operator continues to talk to the woman to keep her on the phone until officers arrive . She asks why she killed her children , and the woman says she wanted normal children . `` They are autistic . I do n't want my kids to be autistic , '' she is heard saying in an even tone . The operator then asks her what she is feeling , and she says `` nothing . '' Akhter is being held in the Dallas County jail in lieu of $ 1 million bail . According to the Texas Department of Family and Protective Services , the Akhter family had a referral in 2009 for `` neglectful supervision . ''
Faryaal Akhter , 2009 , of Irving , Irving , is charged with capital murder . She told the two operator she wanted `` normal '' children . Child services worked with the family in 30 to find resources for their situation .