MADRID — The Bank of Spain warned Wednesday that the country is in a deep recession, a day after clashes in Madrid between protesters and the police led to 38 people arrested and 64 injured.

The demonstrations on Tuesday evening against the government’s austerity drive at a time of mass unemployment put in sharp relief the scale of discontent that’s brewing in a country suffering its second recession in three years and an unemployment rate of nearly 25 percent.

In the wake of the clashes and a warning from the central bank’s that the country’s economy continues to shrink “significantly,” financial markets have grown increasingly nervous. The main IBEX index in Madrid was down a hefty 2.6 percent, while Spain’s 10-year bond yield edged back up toward 6 percent.

On Tuesday, several thousand people — 6,000 according to authorities — converged on the national Parliament building in central Madrid. More than 1,000 riot police blocked off access to the building, forcing protesters to crowd nearby avenues. Police baton-charged protesters at the front of the march and some demonstrators broke down barricades and threw rocks and bottles.

Smaller demonstrations Tuesday attracted hundreds of protesters in Barcelona and Seville.

The protesters are calling for fresh elections, claiming the government’s hard-hitting austerity measures are proof the ruling Popular Party misled voters when it won power last November.