The number of Syrians fleeing to Italy to escape the conflict in their homeland has surged in recent weeks, with about 3,300 reaching its shores in the past 40 days, the United Nations refugee agency said on Friday.

Most of the migrants are families with children and set out mainly from Egypt but also from Turkey. The majority of those interviewed by the United Nations High Commissioner for Refugees (UNHCR) said they came from the Syrian capital Damascus.

Since the start of the year, about 4,600 Syrians have fled by boat to Italian shores and about two-thirds of that number arrived in August alone, UNHCR said in a statement.

About 670 Syrians reached Italy in the past week.

When they arrive, usually at the southern island of Sicily, migrants are taken to immigration centers and some are transferred to hospital suffering dehydration and other health problems.

The Syrian conflict has been going on for two-and-a-half years but speculation about a possible military intervention by Western powers has increased following a chemical weapons attack on a Damascus suburb on Aug. 21.

The United States and other Western powers have blamed the attack on President Bashar al-Assad's forces but his government has rejected the accusation.

Italian officials said on Thursday they had seized a "mother ship" used to traffic illegal migrants across the Mediterranean and picked up about 200 Syrians.

Thousands of migrants, most from North Africa, usually try to reach Italy's southern shores in the summer months, when Mediterranean waters are calm enough for small rickety boats to make the crossing.

The UNHCR said that overall 21,870 seaborne migrants reached Italy between Jan. 1 and Sept. 6 this year, compared to 7,891 people in the same period last year.

Most of the migrants this year come from Eritrea but Syrian migrants are now the second largest grouping, with a total of 3,970 reaching Italy in the period, more than ten times the 369 who arrived between Jan. 1 and Sept. 6, 2012.