There was no word from the government here about 11 personnel of the Pakistan Navy who have gone missing while their ships were on a goodwill visit to Japan.

Although the Pakistan embassy in Tokyo said they had 'disappeared' and expressed regrets and the Japanese government confirmed it, officials here, red-faced over the incident, have refused to comment.

'Eleven personnel from the Pakistan Navy have disappeared. It is a very regrettable incident,' Pakistani embassy spokesman Muhammad Abdul Wahid Khan was quoted as saying in media reports Saturday.

'We have asked Japanese authorities to apprehend the people so that we can immediately deport them and so they can face legal action,' Khan added.

The men were among nearly 700 Pakistani naval personnel aboard the two ships on the Japan visit this week.

Reports from Tokyo said they vanished during a tour of Tokyo city when they stopped in Akihabara district, known for electronics goods and Japan's comic-book subculture.

The navy realised late on Thursday that the men were missing. The two ships, the PNS Moawin and PNS Babur, left Friday without the sailors at the end of the four-day visit.

A Tokyo police spokesman confirmed that the sailors were missing but put their number at 10.

This was only the second time that Pakistani naval ships have gone to Japan, Dawn newspaper said Saturday.

The Pakistani media carried international wire service reports prominently, but without a follow-up or offering any comment.

Separately, Kyodo News Agency said the Japanese Coast Guard complained that one of the Pakistani ships accidentally discharged water contaminated with oil and sewage, causing a two-kilometre spill that was cleaned up.