Italians are angry at the UK for not taking them into confidence before embarking on a mission to rescue the abducted engineers in Nigeria, a charge denied by Britain.

Upset Italians want to know why they were kept in the dark about the rescue mission, the BBC reported Italian Senator Lucio Malan as saying.

"It is quite uncommon that a country that is involved is not informed before. Apparently it was a very difficult situation and it might have been the best decision but it is still to be explained why the Italian authorities haven't been informed," said Lucio Malan on BBC's Newsnight.

Other Italian politicians are also demanding to know the reason behind their country not being informed before the mission.

Downing Street maintained that the Italian authorities were informed about every detail of the rescue mission.

"A Downing Street spokesperson said that the UK had been in regular contact with the Italian authorities throughout the case," the BBC reported.

Italian Prime Minister Mario Monti's office has sought a detailed reconstruction of the events from Nigerian President Goodluck Jonathan, the report said.

British engineer Chris McManus and Italian Franco Lamolinara were abducted by gunmen belonging to a splinter cell of the Nigerian terrorist group Boko Haram on 12 May, 2011.

The two men were killed during a rescue mission authorised by David Cameron on Thursday.