Nearly a million bank workers in India have taken part in a one-day strike in protest at reforms which unions believe will lead to job cuts.
Unions fear thousands of branch closures
The government has been encouraging 27 state-run banks to merge in order to compete better in the global economy.
Unions say the move will result in the closure of 22,000 branches nationwide.
About 50,000 staff at foreign and some private banks did work, but trading volumes on the foreign exchange market were affected.
"Volumes are very thin with limited participation," a dealer at HDFC Bank told the Reuters news agency.
India's booming economy has helped raise demand for banking services.
Last month, the government loosened merger regulations on state banks, which are responsible for handling about 70% of loans and deposits.
Tuesday's strike was called by the United Forum of Bank Unions, made up of nine separate unions.
Employees at the country's largest bank, the State Bank of India, were among those who walked out.
Workers at some of the older privately-run institutions such as Federal Bank and Karnataka Bank were also believed to have taken part.
The strike came after a "sit-in" demonstration in front of the Indian parliament building on 11 March.
A BBC correspondent said an official at a private bank described changes in the industry as "inevitable".
Unions, however, are vowing to continue to protest and said they are deciding on their next course of action.