The bulk carrier Iran Deyanat, owned by Islamic Republic of Iran Shipping Lines (IRISL), was hijacked on Aug. 21, one of numerous ships hijacked by pirates in the waters off the Horn of Africa. It was freed on Oct. 10.

International shipping officials say the attacks are threatening trade near the entrance to the Red Sea, which is on a vital shipping route between Asia and Europe.

One report suggested the Iran Deyanat had been carrying arms to Eritrea, and a Kenyan-based shipping organisation suggested the ship was carrying a "dangerous chemical" that had injured and killed Somali pirates.

IRISL denied both allegations in a statement on Wednesday. It said the Iran Deyanat had sailed to Salalah, Oman, after its release and was now in the Mediterranean, heading to Rotterdam.

"The cargo was loaded in China under normal circumstances and there is no danger associated with it," IRISL said.

"We didn't go to Eritrea with any weapons," Captain Majid Ensan Najib of IRISL told Reuters.

Najib, the head of IRISL's maritime affairs department and emergency response committee, who was involved in Iran Deyanat's release, said the ship's manifest had listed only minerals and industrial goods, not chemicals or arms.

He said IRISL had instructed its ships to take extra precautions in the region.

"We are protecting boarding areas of the ship with barbed wire. We are keeping personnel on standby on deck day and night when passing through the Gulf of Aden," he said.

Ships were also maintaining radio contact with a multinational anti-piracy force.

Ships from the United States, Britain, France, Canada, and Germany are all patrolling the are after the U.N. International Maritime Organisation asked for help to fight piracy.

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