Up to half a million migrants in Libya are preparing to attempt the crossing to Europe, a British military official said Saturday, threatening to exacerbate a crisis facing the region, which has already seen thousands die after taking to sea in ramshackle boats.

Capt. Nick Cooke-Priest, on the British warship HMS Bulwark, told the Associated Press: "Indications are there that there are 450,000 to 500,000 migrants in Libya who are waiting at the border" for voyage from the North African country's Mediterranean coast in hopes of reaching Italian shores.

The Bulwark is part of a multi-national European task force, which has been operating at a frantic pace in recent weeks, as it attempts to rescue migrants on a journey which has claimed thousands of lives.

On Saturday alone, an estimated 3,480 people were rescued from the Mediterranean, in operations that saw ships from the U.K., Germany Ireland and Italy in action, CNN reported.

For such a large number of people to be rescued in such a short period of time is not unusual. Early last month 5,800 people were rescued from the Mediterranean within 48 hours.

Nine wooden boats thought to be converted fishing vessels and six large rubber dinghies were all found drifting around 45 miles off the Libyan coast after issuing distress calls via satellite phone, according to a Reuters report citing the Italian coastguard. There were no reports of casualties.

In addition to the humanitarian crisis caused by the mass migration, which by one estimate has seen 76,000 people cross from Libya to Europe this year, the EU has been faced with a political crisis, as Mediterranean nations seek help in dealing with migrants from their northern neighbors.

European leaders are expected to clash on the subject at the G7 Summit in Germany this week. German Chancellor Angela Merkel has previously said there should be a new EU system that distributes asylum seekers to member states based on their population and economic strength.

The U.K. has indicated, however, that it would oppose any such plan, saying that if migrants and people-smuggling gangs see people being resettled in Europe, it will encourage further migration, according the Guardian.