Updated

There have been four failed pirate attacks in the last 24 hours off the lawless Somali coast despite the presence of six American warships guarding a hijacked ship full of weapons, a U.S. navy spokeswoman said today.

Navy Commander Jane Campbell, from the 5th Fleet in Bahrain, says three attacks were averted because crew members escaped at high speed.

Another attack was foiled because the pirates were badly prepared: The ladder they had brought to climb onto the ship was too short.

The Navy says that three of the attacks were in the heavily patrolled corridor within the Gulf of Aden. The location of another was not precisely known but was somewhere off the Somali coast.

Last week's attack on a Ukrainian ship laden with 33 Soviet-designed tanks and weapons has focused international attention on piracy in Somalia. American officials have expressed fears the weapons onboard the MV Faina could fall into the hands of Somalia's al Qaida-linked Islamic insurgency.

Eight European countries have offered to help form an anti-piracy force. On Friday, Russia called for greater efforts to protect the Gulf of Aden waters, one of the world's most important shipping lanes. There have been nearly 70 pirate attacks this year already and some 26 ships successfully hijacked.