Somali pirates who seized a French yacht and kidnapped two French nationals want a "ransom" of more than one million dollars, a maritime official said Thursday, amid reports that an Egyptian boat had been seized in nearby waters.

Andrew Mwangura, of the Kenya-based Seafarers Assistance Programme, said they had received reports "the gunmen are demanding more than one million dollars in ransom" to release both the yacht and the hostages.

The information could not be independently verified as authorities in Somalia's Puntland region, close to where the boat was attacked, were not able to confirm the claim.

Egypt's junior foreign affairs minister Ahmed Rizk meanwhile said a "boat has been hijacked near Eyl in the Puntland region known for its instability and the scene of many incidents of piracy," the official Mena news agency reported.

He said the Egyptian embassy in Nairobi was trying to ascertain the name of the boat, the size of the crew and their identities.

Hijackers captured the 16-metre French sailing boat Carre d'as in the Gulf of Aden late Tuesday and were taking it to Eyl village, a pirate den in Somalia's northern semi-autonomous Puntland region.

"We can only pray that the pirates release the hostages. We are powerless to help," said Abdullahi Saed Yusuf, the district commissioner of Eyl.

The French foreign ministry said earlier that two French nationals were seized with the Venezuelan-registered boat.

French commandos carried out an operation in April and captured six pirates after Somali pirates seized a French luxury sailing ship, Le Ponant, with its 30 crew, including 22 French nationals, and held them for a week.

Since the end of July, eight ships have been hijacked in the Gulf of Aden, including two Malaysian vessels as well as others from Germany, Iran and Japan.

The waters off Somalia are the most dangerous in the world for pirate attacks, with the International Maritime Bureau reporting 24 attacks in the area between April and June this year.