parseXml() and addChild() inserts an unexpected dtd

[SudeshKumarSK]

articleTag = xmlDoc.root() subArticle_string = fs.readFileSync("/Users/sk/Microbiology_Task/01FirstPreprint/subarticle.xml"); var fragment = libxmljs.parseXml(subArticle_string); articleTag.addChild(fragment);

My Output file had the dtd in between. Is there anyway to add xml fragments into the mail xml file without the dtd being added inbetween?