BOSASSO, Somalia (Reuters) - A Chinese navy ship handed over three suspected pirates to Somali authorities on Friday, police said, underscoring the determination of international naval forces to stamp out a resurgence of piracy this year.

The pirates were involved in the attempted hijacking in April of the OS35, a Tuvalu-flagged cargo ship that was rescued by the Chinese navy after the crew sent a distress call.

“A Chinese navy ship handed over three pirates to Puntland today,” said Ahmed Saiid, the deputy director of maritime police forces in the semi-autonomous northern region of Puntland.

The pirates handed to the Puntland authorities included a local pirate leader known as Aw Kombe, he said.

In their heyday in 2011, Somali pirates launched 237 attacks off the coast of Somalia and held hundreds of hostages, the International Maritime Bureau said.

That year, the Ocean’s Beyond Piracy aid group estimated the global cost of piracy at about $7 billion. The shipping industry bore roughly 80 percent of those costs, the group said.

Attacks fell sharply after ship owners tightened security and avoided the Somali coast. But they have risen again this year and the U.S. navy said it believes the spike is partly driven by severe drought in the Horn of Africa nation.