No demand has yet been made by the hijackers of a ship carrying 22 crew members, including 18 Indians.
"No demand has been made by the hijackers yet, we are still waiting to hear from them," Andrew Mwangura, East Africa coordinator of the Seafarers Assistance Programme (SAP) told IANS from Mombasa, Kenya on Wednesday.
"All crew members on board the ship are believed to be safe," he added.
The ship, MT Stolt Valor, was hijacked by pirates 38 nautical miles off the coast of Yemen in the Gulf of Aden on Monday afternoon while it was on its way from the Suez to Mumbai.
The Hong Kong-registered ship is carrying a cargo of oil and chemicals.
Apart from the Indians, the crew members also include two Filipinos, a Bangladeshi and a Russian.
According to Mwangura, Somali authorities are in touch with the ship's owners.
This is the latest in a series of incidents in which pirates have attacked merchant vessels in the arterial shipping lane in the Gulf of Aden.
The Gulf is between Yemen on the south coast of the Arabian Peninsula and Somalia in the Horn of Africa.
It connects with the Red Sea through the Bab-el Mandeb strait in the northwest.
Meanwhile, the International Maritime Bureau has also sounded an alarm over the upsurge of hijackings in the Gulf of Aden, where more than 50 Filipino seafarers have been abducted since July.