PORT-AU-PRINCE, Haiti — Prime Minister Jack Guy Lafontant of Haiti resigned Saturday over his handling of a failed plan to raise fuel prices that set off a wave of deadly protests.

The abrupt resignation came just before the Chamber of Delegates was to vote on a motion to censure Mr. Lafontant, a first step in asking that President Jovenel Moise name a new prime minister. The prime minister is the second highest-ranking official in Haiti after the president.

Mr. Lafontant faced questions about the riots earlier this month that followed the government’s attempt to raise fuel prices by up to 51 percent as part of an agreement with the International Monetary Fund. At least seven people were killed and dozens of businesses were looted during the unrest.

Mr. Lafontant suspended the fuel increases after the protests erupted, but disturbances continued and calls for the prime minister’s resignation grew, including from the opposition and some business groups.