HANOI - The former chairman of Vietnam's second largest listed bank has been arrested for alleged violations of banking regulations, the Southeast Asian country's public security ministry said on Thursday.

Tran Bac Ha, former head of the state-owned Joint Stock Commercial Bank for Investment and Development of Vietnam BID.HM, or BIDV, was accused of "violating regulations on banking operations", the Ministry of Public Security said on its website.

Police have arrested two other former senior executives at the bank and placed another under house arrest for alleged involvement in the case, the ministry said without elaborating.

Ha, who retired from his position at the bank in 2016, was not reachable by phone.

BIDV said in a statement shortly after the announcement of Ha's arrest that it had been reporting violations by the four executives to Vietnamese authorities.

"BIDV affirms that its entire operations are not negatively affected by the above information," the bank said.

Vietnam's central bank said in a statement the violations happened "several years ago".

"All BIDV operations are normal with stable liquidity and all benefits of customers and depositors are ensured," the State Bank of Vietnam said.

The arrests come amid a widening crackdown on corruption in Vietnam, which has seen the Communist-ruled government launch investigations into hundreds of public officials, and several executives at state-owned enterprises jailed.

BIDV, 95.28 percent owned by the central bank is Vietnam's second-largest listed bank by market value after Vietcombank.

Last month, BIDV said it wanted to issue new shares to KEB Hana Bank, a unit of Hana Financial, which would give the South Korean bank a 15 percent stake.

In June, the Communist Party of Vietnam said Ha and two other executives at the bank had committed violations in lending 4.7 trillion dong ($201 million) to 12 companies involved in a corruption case at Vietnam Construction Bank.

Vietnam has opened 427 corruption cases this year to investigate 889 officials, its chief government inspector said this month.

(Reporting by Khanh Vu and Mai Nguyen Editing by James Pearson and Nick Macfie) ((khanh.vu@thomsonreuters.com; +84 24 38259623; Reuters Messaging: khanh.vu.thomsonreuters.com@reuters.net))