LONDON, Jan 25 (Reuters) - Armed pirates have renewed attacks on merchant ships off Somalia, hijacking one and holding 20 of its crew hostage, an ocean crime watchdog said on Wednesday.
The attacks, one on a United Arab Emirates general cargo ship on Sunday and another launched from a so called "mother ship" last Friday, come only days after a U.S. Navy warship captured a band of suspected pirates with a cache of arms.
"With these attacks we now have a grand total of five ships and around 100 mariners being held hostage in Somalia, it was as many as 200, and some have been held for four months," Jayant Abhyankar, deputy director of the IMB, told Reuters.
The IMB said gunmen stormed the UAE-owned Al Manara 150 nautical miles off the east coast of Somalia, threatened the crew, and are now demanding a ransom for their release.
One industry newspaper on Wednesday reported that the crew were low on drinking water and supplies.
In a second attack, the IMB said pirates in two speed boats, chased and fired machine guns at a dry-bulk ship off Somalia's east coast before giving up on an attempted boarding.
The IMB said the speed boats were launched from a "mother ship" similar to one that launched attacks in the Indian Ocean last November.
The IMB said there had been 38 attacks since last March, including the targeting of oil tankers and cruise ships.
The wave of attacks has badly shaken merchant shipping which relies heavily on key international trade routes that snake down Somalia's coastline -- Africa's longest.
Only at the weekend the U.S. Navy reported it had pursued and caught a suspected pirate ship after receiving a report of an attempted attack.
According to the IMB, the U.S. Navy is interrogating 10 Somali men and 16 of Indian nationality found on board.
The 16 are thought to be crew from a vessel hijacked near Mogadishu and used to attack a number of other vessels.
The U.S. Navy's Fifth Fleet based in the Gulf has issued a warning to merchant shipping to stay at least 200 nautical miles off Somalia's coast.
Somalia has been without a central government since 1991, when rival warlords ousted Mohamed Siad Barre.
In November, the Somali government signed a two-year deal worth $50 million with a U.S. marine security firm in a bid to end piracy.
By Stefano Ambrogi