Thousands of people escaping upheaval in Tunisia have landed on the Italian island of Lampedusa, sparking a humanitarian crisis.

The Italian government declared a humanitarian emergency and appealed for European Union aid at the weekend, with at least 4,000 refugees arriving on the tiny outcrop over the last week.

The immigrants are fleeing poverty and continued unrest in the North African country following an uprising last month that ousted Zine El Abidine Ben Ali, the president.

"We are afraid. The revolution in January has changed nothing, absolutely nothing. We want to find a job in Europe. We are asking the Italian people for help," one man told news channel SkyTG24.

Italy's government has handed local authorities, who are used to dealing with just 6,000 residents, extraordinary powers to control migrant flows.

The foreign minister has called for countries around the Mediterranean sea to mobilise boats, aircraft and helicopters to help with the situation.

Catherine Ashton, the EU's foreign policy chief, is set to visit Tunisia on Monday.

Many immigrants have been airlifted or ferried to detention centres in Sicily or mainland Italy, but police say that at least 2,000 remain on the island.

One boat sank off Tunisia's coast on Saturday, leaving at least one person dead, while witnesses have told Al Jazeera that many more may have drowned after a fishing boat carrying scores of people was rammed by a Tunisian coastguard boat.

Italy has called for an urgent EU meeting to work out an efficient response and it wants patrol boats stationed near the Tunisian coast to intercept migrants.

Asked how the Tunisian authorities would respond to the migrant problem, Tayeb Baccouche, a government spokesman, told the Reuters news agency: "This is a response for the security forces".

"We need to discuss this in the cabinet once we have been alerted by the Italian government because we have not yet been informed directly by the Italian government," he said.