DHAKA: Pro-Russian rebels in eastern Ukraine on Saturday freed four Ukrainian prisoners a day after the two sides exchanged hundreds of captives.

The release was announced by a Ukrainian defence ministry adviser, Vasyliy Budik, who said three were soldiers and the fourth a civilian.

On Friday, rebels freed 146 prisoners for 222 people held by the government, in the biggest such swap to date, reports BBC.

President Petro Poroshenko greeted those freed on Friday at an airport.

Elsewhere, Ukraine has frozen vital bus and rail links with Crimea, its southern peninsula annexed by Russia in March.

Crimea has no land corridor to Russia, and relies on a ferry in the Azov Sea and flights from Russia.

The latest moves come ahead of the traditional holiday season in the region, when people travel to be with their families for New Year.

The releases are part of a 12-point peace plan agreed in September, which also included a ceasefire. Fighting continues, however, and more than 1,300 people have died since the truce was announced.

BDST: 1228 HRS, DEC 27, 2014