The agency raided 10 places in Mumbai, six each in Ahmedabad and Bengaluru, four in Chennai, three in Surat, two each in Bihar, Lucknow, Jalandhar and Hyderabad and one in Delhi.
The raids are also being carried out at diamond merchant Nirav Modi's house in Mumbai's Worli.
Meanwhile, the Punjab National Bank on Monday said it will honour all its "bonafide commitments" under the Letters of Undertaking (LOUs) and Foreign Letters of Credit (FLCs) in connection with the colossal banking fraud involving billionaire jewellers Nirav Modi and Mehul Choksi.
LOUs have been used to defraud PNB, the country's second largest bank, to the tune of Rs 11,384 crore.
Meanwhile, CBI continued to question arrested bank officials -- Gokulnath Shetty (retired) and Manoj Kharat, and the signatory of Nirav Modi's company. It also continues to question other officials of PNB to find out the money trail and depth of the alleged scam involving thousands of documents and digital records.
The CBI is also examining financial transactions of 18 India-based subsidiaries of the Gitanjali group of companies promoted by Choksi to understand the money trail of funds taken from various banks on the basis of Rs 11,384 crore of guarantees furnished by Punjab National Bank, officials said here.
PNB, in a notice posted on its website, said: "We will honour all our bonafide commitments under LoUs and FLCs as per law of the land and as per specific existing guidelines of regulator i.e. RBI on LOUs and FLCs."
The Reserve Bank has said that it has not directed PNB to meet its commitments under the LOU to other banks.
The banking sector regulator said however that the fraud at PNB is a case of operational risk arising on account of delinquent behaviour by one or more employees of the bank and failure of internal controls.
RBI added that it has already undertaken a supervisory assessment of control systems in PNB and will take appropriate supervisory action.
Besides CBI, the case is also being investigated by other central agencies including Enforcement Directorate and Income Tax Department.
Markets regulator Sebi too is looking into the fraud case that has adversely impacted the stock markets.
The PNB scrip on NSE touched a 52-week low of 113.55 during intra-day trade, before closing at Rs 115.1, down 8.32 per cent.