Two skiffs with men onboard armed with automatic weapons and RPGs fired upon the vessel. The captain conducted evasive maneuvers and counter-piracy measures while a Turkish warship nearby dispatched two helicopters to provide assistance along with a Danish warship. The men in the two skiffs fled the scene after the warships’ arrival, but no arrests were made. The vessel escaped but reported 40-45 shots around the bridge with minimal damage.No injuries. (ONI Worldwide Threat to Shipping, 03/18/09)
The Vietnamese-owned vessel "transmitted SOS signals off the southern shore of Yemen" which attracted the Turkish rescue. (VietnamNet 03/18/09)
According to Vietnamese sources and Morningstar,
This was the first time the Turkish destroyer TCG Giresun joined the anti-piracy forces. The destroyer joined international naval forces at the Gulf of Aden two weeks previous. Giresun and the Danish warship HDMS Absalon immediately responsed after receiving the emergency from the Vietnamese cargo ship. Helicopters from the Turkish and Danish warships prevented the pirates from taking over the Vietnamese ship.(Wikipedia, "List of ships attacked by Somali pirates," 12/31/09)
