A band of Somali pirates are demanding that the South Korean government pay them compensation for pirates killed by its navy.

The pirates made its demand Friday to media outlets. As a bargaining chip, they are holding four South Korean hostages taken during the hijacking of the MV Gemini off the Kenyan coast several months ago.

South Korean commandos killed eight pirates at the beginning of this year when they stormed a captured ship and rescued 21 hostages.

The South Korean government has not issued a public response to the pirates' demands. It also is not clear how much money the pirates are demanding.

On Thursday, the London-based International Maritime Bureau — which monitors maritime affairs — said the number of pirate attacks off Somalia's coast rose to a record high during the first half of this year.

It also said the raids have grown increasingly bold and violent.

In the group's latest report, it said piracy worldwide jumped 36 percent in the first half of this year. The number of attacks during that period was 266, compared to 196 in the same period last year.

The global group's director, Pottengal Mukundan, also said Somali pirates are taking higher risks. The group said that for the first time, pirates tried to seize a ship during the monsoon season in the Indian Ocean.

Somali pirates continue to terrorize shipping in the Indian Ocean and Arabian Seas despite international naval patrols.

The pirates have hijacked dozens of ships and made hundreds of millions of dollars from ransom payments in the past few years.