By Jack Kimball
NAIROBI (Reuters) - Somali pirates have hijacked a Turkish bulk carrier on its way to Mombasa and abandoned three Indian boats seized off the coast of Somalia due to fuel shortages, maritime advocacy groups said on Wednesday.
Over the last few years sea gangs have seized dozens of ships, including large oil tankers, in the Indian Ocean and Gulf of Aden.
They are expected to try to capture more vessels due to good weather in the coming months despite patrols by foreign warships.
India said last week it was trying to trace the whereabouts of nearly 100 sailors on seven Indian vessels taken captive.
"There are about three of them that were abandoned. The crews are still there. The first two boats got assistance, but the other one we don't know," Andrew Mwangura of the East African Seafarers' Assistance Programme told Reuters.
Another maritime advocacy group, Ecoterra, confirmed three Indian cargo dhows -- MSV Krishna Jyot, MSV Al Kadri and MV Safina al-Bayatiri -- had been released by pirates.
It said the pirates were holding six more cargo dhows.
Al Shabaab, an Islamist group fighting Somalia's western-backed government, has condemned the attacks on ships serving Somali businessmen and asked pirates to desist from capturing them.
Somali pirates have made millions of dollars in ransoms by seizing ships off Somalia's coast and have increased their range using motherships to launch attacks.
Mwangura said the Turkish flagged bulk carrier -- Yasin C -- with 25 crew that had come under attack earlier in the day some 250 nautical miles east of the port of Mombasa had been seized.
Mwangura had said earlier they were yet to determine where it was coming from, or the cargo it was carrying.
He added that hijacked South Korean-operated, Singapore-owned Samho Dream, which can carry more than 2 million barrels of crude, seized on Sunday en route from Iraq to the United States, had reached Somali waters.
U.S. and Omani naval vessels said they had thwarted an attack on Monday by several pirate ships on a vessel, Rising Sun, and saved most of the crew of an Indian boat held hostage by the pirates, the U.S. Navy's Fifth Fleet said in a statement.
"As the Omani ship approached, the nine hostage sailors from Faize Osamani jumped into the ocean in an attempt to get away ... however, one crew member drowned," said the statement, adding that 10 suspected pirates were detained by the U.S. destroyer McFaul.
(Additional reporting by George Obulutsa in Nairobi and Firouz Sedarat in Dubai; editing by Philippa Fletcher)