About 20,000 people took part in the work stoppage in northern Lower Saxony state and nearby Bremen city-state, according to organisers, Verdi, Germany's leading service industry trade union.
Verdi is demanding a 6.5 percent increase in salaries this year for two million workers and has rejected an offer made last week for a 3.3 percent rise over two years.
Further talks are scheduled for March 28 and 29 but Verdi plans to step up the action which has hit hospitals, public transport, kindergartens and public administration offices, before then.
On Tuesday and Wednesday, the strike will extend to four other states in the west and south of Germany, it said.
Some 130,000 people took part in a first wave of strike action across the country at the beginning of the month.