London, Aug 2 (AP) Britain and Iran issued warnings to each other's diplomats on Monday as tensions escalated over a recent attack on an oil tanker in the Arabian Sea.

Britain began the day by summoning Iran's ambassador, Mohsen Baharvand, to the Foreign, Commonwealth & Development Office in response to Thursday's drone strike on the MV Mercer Street, which killed a British national and a Romanian.

Minister James Cleverly, who oversees Middle East affairs, "reiterated that Iran must immediately cease actions that risk international peace and security, and reinforced that vessels must be allowed to navigate freely in accordance with international law," the Foreign Office said in a statement.

The United States, Britain and Israel have blamed Iran for the fatal attack, though Iran denies involvement.

Calling it an “unlawful and callous attack,” British Foreign Secretary Dominic Raab said Sunday that the UK and its allies were planning a coordinated response.

Iran's Foreign Ministry on Monday summoned the British charge d'affaires in Tehran to protest Raab's comments. Iran rejected and strongly condemned these “hasty, contradictory and unsubstantiated statements,” the ministry said.

Iran will defend itself with a timely, appropriate and decisive response to any "adventurous action," the ministry said.

The ministry added that this is not the first time that Britain has made accusations against Iran without providing evidence.

The attack on the Mercer Street is the first known fatal strike on commercial shipping in the region after years of tensions over the tattered nuclear deal between western nations and Iran. (AP)

(The above story is verified and authored by Press Trust of India (PTI) staff. PTI, India’s premier news agency, employs more than 400 journalists and 500 stringers to cover almost every district and small town in India.. The views appearing in the above post do not reflect the opinions of LatestLY)