The European Union warned India against barring the Italian envoy from leaving the country the country embroiled in a deepening standoff with Rome over the killings of two fishermen.

The bloc said the Supreme Court’s order preventing Italian ambassador Daniele Mancini from leaving was contrary to the 1961 Vienna Convention, which sets rules for diplomatic relations, Reuters reported.

The top court revoked the Italian ambassador’s diplomatic immunity and said he could face contempt charges until two Italian marines thought responsible were sent back to stand trial.

EU foreign policy chief Catherine Ashton noted the Indian court’s ruling on the ambassador “with concern”, Ashton’s spokesman said.

“Any limitation to the freedom of movement of the ambassador of Italy to India would be contrary to the international obligations established under this convention,” the spokesman added.

“Ashton continues to hope that a mutually acceptable solution can be found through dialogue and in respect of international rules and encourages the parties to explore all avenues to that effect,” the bloc said in a statement.

EU spokesman Michael Mann said it was “imperative” for India to respect the Vienna convention and the diplomatic immunity granted to Mancini.

Italy’s Foreign Ministry on Monday said the Indian court’s decision violated diplomatic immunity law.

Mancini promised to return Massimiliano Latorre and Salvatore Girone after they were allowed to fly home to vote in the general election. Italy refused to send the marines back, arguing the pair would be tried there, sparking uproar in India.