A letter sent by the Dutch foreign and defence ministers explaining the failure of a mission to rescue a Dutch and a Swedish national in Libya has been strongly criticised by opposition parties in parliament.

When three Dutch soldiers landed in the port city of Sirte at the end of last month, they were captured by pro-Gaddafi forces and held for 12 days. In their letter, the foreign and defence ministers have tried to explain to parliament what went wrong. But opposition parties charge that the letter raises more questions than it answers.