Rome:  Italy on Tuesday sent a top diplomat to India and said Foreign Minister Giulio Terzi will visit next week amid an escalating row over two Italian soldiers arrested for killing two Indian fishermen.

Junior Foreign Minister Staffan De Mistura will "continue on a political level the action so far carried out by a delegation of experts from the Italian foreign, defence and justice ministries," the Foreign Ministry said in a note.

"Minister Terzi will visit personally next Tuesday," the note said.

The Foreign Ministry also said that Indian police had taken "coercive" and "unilateral" action when it escorted the two soldiers off the oil tanker where they were deployed as security guards and arrested them on Sunday.

The soldiers, Massimiliano Latorre and Salvatore Girone, members of the elite San Marco Marine regiment, were on board the tanker to guard against piracy and Italy has said they mistook the fishermen for pirates.

The tanker was sailing from Singapore to Egypt when the incident took place.

Italian authorities insist that the men should not be prosecuted in India as the tanker, the Enrica Lexie, was flying under an Italian flag in international waters when the shooting occurred on Wednesday off southern India.

Italy's Defence Ministry has claimed the Indian fishing boat behaved aggressively and was repeatedly warned before shots were fired. It said the officers fired warning shots and the boat left "with no obvious damage."

But India has protested fiercely against the deaths of the unarmed men and said that the suspects must face justice in local courts.