A migrant boat with some 700 people onboard capsized off the Libyan coast on Wednesday and only around half have been rescued so far, Italian reports said.

According to ANSA news agency, the accident happened when migrants attempting the Mediterranean crossing to Italy moved all together towards the same side of the boat to ask for help when they saw some vessels approaching them.

The Italian Coast Guard, which is coordinating rescue operations among various vessels in the area, said an alarm came in late morning via a satellite telephone call.

The migrant issue has made the Italian headlines in recent months, which have seen the countless arrivals of migrants fleeing North African poverty- and unrest-stricken nations via Mediterranean Sea into the southern coasts of Italy.

The International Organization for Migration (IMO) said earlier this week that more than 2,000 migrants have died so far this year at sea while trying to reach European shores.

European leaders have met several times on the issue and have recently launched a naval operation against human traffickers in the Mediterranean who make business out of migrants' despair.