* Tankers en route to Somalia
* Pirates extending range
(adds Greek firm's comment)
By Alison Bevege and Andrew Cawthorne
NAIROBI, March 27 (Reuters) - Pirates were taking two European-owned tankers to Somali coastal havens on Friday and are likely to demand ransoms soon, with gangs striking further afield to avoid patrolling warships, maritime groups said.
Andrew Mwangura, coordinator of the East African Seafarers Assistance Programme, said the ships, hijacked on Wednesday and Thursday, appeared to be en route to well-known pirate bases at Eyl or Hobyo on Somalia's Indian Ocean coastline.
"How long it takes depends on the water current and the speed of the boats," he said, guessing that a demand for money from the ships' owners would come in the next 24 hours.
The 9,000-tonne MT Nipayia and the 23,000-tonne MT Bow Asir were seized within 24 hours in the biggest strikes since international naval forces deployed en masse at the end of 2008 to protect the region's busy sea lanes.
The Nipayia, a Greek-owned and Panama-registered ship with a Russian captain and 18 other Filipino crew on board, was taken on Wednesday 450 miles east of Somalia's south coast, the European Union and NATO said on piracy-monitoring websites.
The Bow Asir, a Norwegian-owned and Bahamian-registered ship, was seized on Thursday 250 miles east of the coast. Its 27 crew include a Norwegian captain, 19 Filipinos, five Poles, one Russian and one Lithuanian, owners Salhus Shipping has said.
Flush with millions of dollars from ransoms for previous hijackings, the pirates are using ever-more sophisticated boats and equipment, as well as sinking their money into new houses, flashy cars and extra wives onshore.
Most began life as poor fishermen, and many unemployed youths in the Horn of Africa nation, mired in civil conflict since 1991, now see piracy as the only chance to strike it rich.
FOREIGN PATROLS
Avoiding the now heavily-patrolled Gulf of Aden -- the gateway to the Suez Canal -- Somali pirates are striking ever further east and south in the Indian Ocean.
They also took a yacht en route from the Seychelles to Madagascar earlier this week.
Eager to protect some of the world's most important shipping lanes, the United States, various European nations, Russia, India, China and Japan have all sent ships.
"They can more or less protect the Gulf of Aden, but with the Indian Ocean it's like the old proverb of looking for a needle in a haystack," a diplomat monitoring piracy said.
The Bow Asir has a full cargo of caustic soda, whereas the Nipayia is empty, Mwangura's group says.
The Norwegian Shipowners Association said there had been no contact with the Bow Asir since Thursday, adding no ransom demand had been received.
Athens-based Lotus Shipping Company, manager of the Nipayia, said the ship was bound for the Persion Gulf when captured.
"The safety of our crew, and of the vessel, is the paramount concern. The owners are resolved to do everything that they can to ensure their safe release," it said in a statement.
In the last week, there have been 11 strikes in the remoter waters, Mwangura said, showing the shift in pirate strategy. "They are concentrated to the south-east of Mombasa, north of Madagascar and nearby to the Seychelles," he said.
The International Maritime Bureau (IMB) says there have been seven successful hijackings by Somali pirates so far this year, compared with a record number of 42 in 2008. There have also been 44 unsuccessful attacks since the start of 2009.
Pirates are now holding nine ships for ransom with around 137 crew members hostage, the IMB said.
Typically, gangs operate from a "mother" ship that will launch faster speedboats, full of armed men, to board the target. Most crews surrender without a fight. (Additional reporting by John Acher in Oslo and Renee Maltezou in Athens; Editing by Katie Nguyen)