The four, a German family of three and a French captain, were seized on Monday near the coastal town of Lasqorey, Puntland senior presidential adviser Bile Mohamoud Qabowsade told reporters.

"They were four tourists -- two men, a woman and a child. They were taken by pirates after they came close to the coastal area and we are trying to trace them by deploying our forces around the area," he said.

The official said the foreigners were taking pictures from their small yacht when the pirates snatched them, took them ashore and spirited them away into the neighbouring mountains.

Other officials said they were trying to confirm the four abducted tourists were German.

Dangerous waters

Somalia's waters are among the most pirate-infested in the world and all countries have issued warnings against sailing too close to the shore.

Earlier this month, the United Nations Security Council adopted a resolution allowing foreign states to dispatch their military to combat piracy.

Dozens of ships, mainly merchant vessels, have been hijacked for ransom off the Somali coast over the past year.

Somalia juts out into the Indian Ocean and commands access to the Red Sea, a key global trade route sailed by thousands of ships each year.

On April 4, pirates seized a French luxury yacht off Somalia and held its 30-person crew hostage for a week.

French soldiers hunt pirates

French forces subsequently went into pursuit of suspected pirates on Somali soil and arrested six of them for trial in a Paris court. The move set a precedent in combating piracy and was welcomed by the Somali government.

Piracy off Somalia's long coastline has also hampered efforts to deliver humanitarian assistance to a country devastated by more than 17 years of almost uninterrupted civil war.

The UN's food agency earlier this month requested states to volunteer their navy to escort food shipments.

The WFP stressed that 80 percent of its food aid to Somalia arrives by sea. From mid-November French, Danish and Dutch frigates escorted enough food to feed nearly one million people for six months.

The UN's Office for the Coordination of Humanitarian Affairs warned earlier this week that up to 3.5 million Somalis will need humanitarian aid this year if the situation in the war-wracked east African nation fails to improve.