Demonstrators also targeted the road to the airport and near the city of Baalbek while others shut down a foreign exchange bureau in the southern city of Sidon, local media said.
The financial collapse, on a scale Lebanon has never seen, has slashed about 85% of the currency's value in a country relying heavily on imports.
The cost of scarce dollars hit 10,000 Lebanese pounds on Tuesday, said three currency dealers on the informal market, a main source of cash since banks stopped dispensing dollars. Two other dealers said earlier the greenback had traded at 9,900.
That makes Lebanon's minimum wage worth about $68 a month.
Political leaders have failed to agree a rescue plan since the crisis, rooted in decades of state graft, erupted in late 2019 as dollar inflows dried up.
At the time, protests had gripped the country, fuelled by anger over economic hardship and new tax plans, including a daily 20-cent fee on Whatsapp calls.
Prices of many consumer goods such as diapers or cereals have nearly tripled since then and charities warn of rising hunger.