Greece's coast guard says nearly 12,000 immigrants were arrested entering the country illegally last month — an almost seven-fold increase from the previous year.

The agency said Wednesday that 11,873 people were arrested in April and 6,583 were arrested in March — nearly all on islands facing the coast of Turkey.

Migration Commissioner Dimitris Avramopoulos, on a visit to Athens Tuesday, said he would back a European Union relocation plan to assist Greece and Italy.

Greece's government has welcomed the plan but is seeking a higher quota, to help it cope with large numbers of arriving from war-torn Syria.

According to government estimates, some 37,500 immigrants and asylum seekers have reached Greece illegally so far this year.