Iran has asked India to release three tankers seized in February as part of ongoing discussions aimed at ensuring the safe passage of Indian-flagged or India-bound vessels through the Strait of Hormuz, according to three sources familiar with the matter.

Indian authorities seized the three Iran-linked tankers near Indian waters, alleging that they had concealed or altered their identities and were involved in illegal ship-to-ship transfers at sea.

Tehran has also sought supplies of certain medicines and medical equipment, according to one of the sources, an Iranian official.

Iran’s ambassador to New Delhi met officials from India’s Ministry of External Affairs on Monday to discuss the issue, the source said. The sources spoke on condition of anonymity due to the sensitivity of the matter.

India’s foreign ministry, the Iranian embassy in New Delhi, and Iran’s foreign ministry did not immediately respond to requests for comment.

Iran recently allowed two Indian liquefied petroleum gas (LPG) tankers to pass through the strait, according to Indian officials, and one of them returned to western India on Monday. Shipping traffic on both sides of the strait has slowed sharply since the outbreak of the conflict in Iran.

Asked about negotiations to ensure passage for Indian vessels, foreign ministry spokesperson Randhir Jaiswal said recent movements reflected a “history of engagement, of dealing with each other.”

Speaking at a regular briefing, he said no exchange or deal was taking place.

Since the start of U.S. and Israeli attacks on Iran in late February, Tehran has launched retaliatory strikes across the region, including attacks on ships attempting to transit the Strait of Hormuz. Three Indian sailors were killed in the incidents and one remains missing.

India said on Monday that at least 22 Indian-flagged vessels and 611 Indian seafarers remained in the Gulf.

An Indian source said six of the vessels were carrying LPG, and New Delhi was keen to secure their passage first to ease a shortage of the cooking fuel. About 90% of India’s LPG imports come from the Gulf region.

Iranian-linked tankers anchored off Mumbai

Indian authorities seized the tankers Asphalt Star, Al Jafzia, and Stellar Ruby, alleging that they had concealed or altered their identities and movements and were involved in illegal ship-to-ship transfers.

Stellar Ruby sails under the Iranian flag, while the other two vessels are registered in Nicaragua and Mali.

A police complaint filed by the Indian Coast Guard on February 15 said Asphalt Star had transported heavy fuel oil that was transferred to Al Jafzia, while bitumen was transferred to Stellar Ruby. All three vessels are currently anchored off Mumbai.

Around the time of the seizure, Iranian state media quoted the National Iranian Oil Company as saying that the three vessels had no connection to the company.

Jugwinder Singh Brar said he had served as a consultant for the three ships seized by India and insisted they had done nothing wrong.

“We were transporting bitumen and there is nothing illegal in doing this. My ships have been there for 40 days and I have suffered losses,” he said by phone, adding that he was not aware of any negotiations over the tankers.