ROME (Reuters) - More than 700 migrants were rescued from six leaky boats in the sea between Tunisia and Sicily on Tuesday and four were found dead, the Italian navy said.

More than 400 migrants have died in the Mediterranean this year, as people continue to try to cross into Europe despite bad winter weather in the second year of Europe's biggest migration crisis since World War Two.

More than 110,000 people, many fleeing poverty and war in Africa and the Middle East, have arrived in Greece and Italy this year, a sharp increase on 2015, according to the International Organization for Migration (IOM).

The navy said one of its ships went to help three boats, recovering 403 survivors and the four bodies. Another ship rescued 219 people from two vessels and a third coordinated the rescue of 105 migrants from their sinking boat.

The navy did not say what nationality the migrants were nor did it give any other information about their identities.

Bad weather cut the number of people arriving last month in Greece, the main gateway to Europe for migrants, but the number was still nearly 40 times higher than in the previous January, European Union border agency Frontex says.

Most of those were from Syria, Iraq and Aghanistan, while most of those who entered Europe via Italy were Nigerian, according to Frontex.

Italy called on Monday for shared funding, including through issuing EU bonds, for a common policy to manage external borders and cope with the migration crisis.

 

(Reporting by Isla Binnie; Editing by Louise Ireland)

 

 

* 110,000 have arrived in Greece, Italy in 2016 - IOM

* UNHCR calls for "unified approach" to deal with crisis

* Decries restrictions imposed by Austria, Slovenia, Macedonia (recasts with UNHCR statement, quotes, byline)

By Stephanie Nebehay

GENEVA, Feb 23 (Reuters) - The number of migrants and refugees arriving in Italy and Greece since the start of the year has risen sharply compared to the same period 2015 and hundreds are stranded at European borders due to rising restrictions, aid agencies said on Tuesday.

At least 102,500 people have landed on Greek islands including Samos, Kos and Lesbos this year, and 7,500 in Italy, the International Organization for Migration (IOM) said in a statement.

"We've reached that figure in two months as opposed to last year when it was reached by the summer," IOM spokesman Itayi Viriri told a news briefing.

In 2015, the 100,000 mark was not reached until the end of June, according to IOM figures. The vast majority of the latest arrivals are from Syria, Afghanistan and Iraq, IOM said.

In a separate statement, the United Nations refugee agency called on European countries to take a "unified approach" and denounced restrictions limiting access for asylum seekers, including some based on nationality.

Referring to caps imposed by Austria and Slovenia, the UNHCR said: "These newest restrictive measures risk violating EU law and undermine efforts for a comprehensive and coordinated approach to deal with the refugee and migrant crisis in Europe."

Most of the refugees are fleeing war and persecution and deserve protection, including Syrian refugees from fierce fighting in Aleppo, the U.N. High Commissioner for Refugees (UNHCR) said in a statement.

"And yet, with every passing week, it appears some European countries are focusing on keeping refugees and migrants out more than on responsibly managing the flow and working on common solutions."

Last week Austria, Slovenia, Croatia, Serbia and the former Yugoslav Republic of Macedonia agreed to jointly profile and register refugees at the border between Macedonia and Greece, which had resulted in "increased protection risks", UNHCR said.

Austria and Slovenia's daily cap on asylum seekers and their joint restrictions with the other three countries had left nearly 700 people, mainly Afghans, barred from crossing from Macedonia into Serbia, UNHCR said.

Macedonia's own restrictions also left hundreds stranded at border crossings from Greece, where police started removing them on Tuesday, sources said.

More than 410 have died so far this year at sea, mostly on the route from Turkey to Greece, the IOM said.

(Reporting by Stephanie Nebehay; Editing by John Stonestreet and Raissa Kasolowsky)