Nairobi (Kenya), Nov.19 Somali pirates have attacked the US ship Maersk Alabama for the second time in seven months, but were thwarted by private guards on board.

A U.S. surveillance plane was monitoring the ship as it continued to its destination on the Kenyan coast.

Somalian pirates hijacked the Maersk Alabama for the first time last April and took ship captain Richard Phillips hostage, holding him at gunpoint in a lifeboat for five days.

Navy SEAL sharpshooters freed Mr. Phillips while killing three pirates in a daring nighttime attack.

Four suspected pirates in a skiff attacked the ship again on Wednesday about 6:30 a.m. local time, firing on the ship with automatic weapons from about 300 yards away, a statement from the U.S. Fifth Fleet in Bahrain said.

An on-board security team repelled the attack by using evasive maneuvers, small-arms fire and a Long Range Acoustic Device, which can beam earsplitting alarm tones, the fleet said.

Vice Adm. Bill Gortney of the U.S. Naval Forces Central Command said the Maersk Alabama had followed the maritime industry's "best practices" in having a security team on board. (ANI)