MOGADISHU, Somalia — Pirates killed five crew members of a hijacked fuel tanker before security forces retook the vessel off Somalia, authorities in the country’s semiautonomous Puntland region said.

The MT Honour 25 was seized in April with 17 crew members aboard, one of a growing number of piracy incidents in Puntland. The tanker was carrying 18,500 barrels of oil.

Sixteen suspected pirates were detained following the operation on Tuesday, and at least 11 others escaped and remain at large, authorities said.

The victims include three Pakistanis, one Myanmar national and one Indian, the Puntland Maritime Police Force said Tuesday. Four others, including three Pakistanis and one Indian, were injured.

The tanker was secured and placed under the protection of Puntland authorities, according to a statement by the Puntland Maritime Police Force. The pirates are believed to have kept the crew supplied with food during the hijacking.

Pakistan’s Ministry of Foreign Affairs said it was “deeply saddened by the tragic loss of five crew members during the operation to recover the hijacked vessel.”

The rescue operation was the latest in a series of anti-piracy operations along Puntland’s coastline.

Puntland police also responded to the hijacking of the oil tanker MT Eureka, which was seized in May. It said pirates ran the vessel aground before abandoning it and having the crew disembark. Crew members were later confirmed safe, according to the statement.

The cases have fueled renewed concerns over a resurgence of piracy off Somalia’s coast after years of relative decline in attacks.

Puntland authorities say they will continue pursuing those involved in piracy and other maritime crimes, and seek continued cooperation with international maritime security partners.