Pirates holding a Spanish trawler off Somalia took three crew members ashore Thursday to press Spanish authorities for the release of fellow pirates captured in connection with the month-old hostage drama, wives of two sailors said.

Later, in a telephone interview broadcast by on Spanish TV, Ricardo Blach, the skipper of the hijacked Alakrana, said pirates on board had threatened to kill the three crew members taken ashore, if there was no progress in freeing the two pirates currently being held in Spain.

A total of 36 crew members were taken hostage when of the Alakrana was seized on Oct. 2 in the Indian Ocean waters. It is now being held just off the coast of Somalia.

"They told us an hour ago that if there is no movement relating to those who are in Spain, then they would begin by killing those three in three days time, and then they would take another three, and so on," Blach said.

In another development regarding the surge of piracy off Somalia, brigands on Thursday captured a Greek-owned bulk carrier with 21 crew on board, according to an EU naval force fighting piracy in the Indian Ocean. The carrier, which is flagged in the Marshall Islands, had been heading to Zanzibar but was last seen 300 miles east of Mombasa, Kenya, the force said.

That hijacking brought the number of crew being held by Somali pirates to more than 210 from 10 captured vessels. A retired British couple taken late last month from their private yacht remain captive in Somalia.

Spain's defense minister confirmed three crew members had been removed from the commandeered Spanish tuna trawler Alakrana and taken on a smaller boat to Somalia. But she would not comment on what the pirates' motives might be.

"We know exactly where they are and we also know that they are OK," Carme Chacon told a news conference. "We know that in order to achieve their criminal aims, pirates not only hold crew members but also exploit the anxiety of their families."

Two Spanish wives said they had spoken by cell phone Thursday with their husbands, who are among Alakrana's crew.

Pirates on the ship ordered some crew members to call home Thursday and tell their families that three colleagues were being taken to Somalia, Chacon said. The government is working on all fronts to free the entire crew and does not rule out any option, including military action, she said without giving details.

In April 2008, the Spanish government reportedly paid a euro1.2 million ($1.78 million) ransom to secure the release of the Spanish trawler Playa de Bakio, which had been captured by pirates off Somalia's coast. In the end, it was held for six days.

One of the women who spoke Thursday, Silvia Albes, the wife of sailor Pablo Costas, described him as very frightened. Costas said the ship is running out of drinking water and conditions are increasingly desperate.

"My husband said they have taken three crew members off the ship," Albes told Spanish National Radio.

Costas said the crew "are all very scared. My husband was crying. There came a point when all he could say was 'I love you, I love you, I love you. Please get me off the ship,"' Albes said.

Pirates on the Alakrana fired a rocket-propelled grenade into the water and fired guns into the air to ward off a Spanish navy frigate that is shadowing it, a Defense Ministry official said, speaking on condition of anonymity in line with ministry rules.

Two days after the hijacking, Spanish naval forces taking part in the EU anti-piracy mission captured two suspected pirates as they tried to travel ashore to Somalia from the Alakrana in a skiff. Both are now in custody in Madrid and face preliminary charges, including 36 counts of kidnapping.

The pirates who remain on the Spanish ship want those two released as a condition for freeing the Alakrana and the crew, said the other wife, Maria Angeles Jimenez, who is married to sailor Gaizka Iturbe.

He told Jimenez the pirates are threatening to take more crew ashore if the two detained colleagues are not freed.

The minister, Chacon, dodged a question as to whether these two might in fact be released. She said the Spanish naval forces who caught them were fulfilling their mission to prevent piracy and arrest those caught doing it. Albes and other family members have complained that heavy publicity surrounding the arrests complicate the task of freeing the fishermen.

Jimenez said, "The government is ignoring what the kidnappers have brought to the negotiating table. Their main demand is that the two Somalis be returned."

"And if they are not returned, they have already taken three crew members off the ship and they are going to keep taking them off one by one," she added

Jimenez, too, said her husband had broken down in tears. "And he told me, 'Go tell the press. Scream. Make noise. Don't leave me."'