ROME (Reuters) - Italy's coastguard said on Friday it had intercepted eight flimsy and rickety boats carrying more than 470 migrants, mostly from Africa, who were attempting to reach Italian shores over the past two days.

Italy bears the brunt of clandestine seaborne migration to southern Europe. Most migrants risk the voyage across the Mediterranean Sea in small and overcrowded fishing boats.

Thousands have died as a result of shipwreck, harsh conditions at sea or a lack of food and water in recent years, activists say.

"With the arrival of the spring and the subsequent improvement in the weather conditions, migrant attempts to reach the Italian coast have picked up massively," the coastguard said in a statement.

A 15-metre long rubber boat carrying 98 people from sub-Saharan Africa was intercepted 96 miles off the coast of the tiny Sicilian island of Lampedusa on Thursday, a coastguard official said.

Rescue workers then received an emergency call from another boat carrying 131 people from sub-Saharan Africa, Pakistan and Bangladesh close to Lampedusa, which they brought to shore.

Overnight the coastguard rescued 31 people from Morocco and sub-Saharan Africa on a boat off the southern coast of Sicily, which was also heading to Lampedusa.

The official said 214 other migrants, mainly from Africa, on five boats had also been detained in the past 48 hours.

All the migrants are being held in reception centers in Sicily and Lampedusa, the official said.

Maltese authorities intercepted 90 migrants in Maltese waters late on Thursday.

An estimated 1,500 migrants lost their lives in the Mediterranean in 2011 during the Arab Spring uprisings in North Africa, according to Human Rights Watch. It estimates the death toll in 2012 at more than 300.

(Reporting By Catherine Hornby; Editing by Pravin Char)