Pro-Russia rebels cement hold on disputed Ukraine airport

Pro-Russian rebels cemented their hold Friday on a long-disputed airport ceded by Ukrainian troops during an upsurge in clashes that killed nearly 50 people and punctured Europe's latest push for peace in the nine-month war.
      
The deadliest day of fighting since the signing of an increasingly irrelevant September truce also saw Moscow and Kyivon Thursday trade bitter blame for a trolleybus shelling in the rebel stronghold of Donetsk that killed 13 mostly elderly passengers.
      
Moscow called the incident a "crime against humanity" orchestrated by a pro-Western government whose rise to power 11 months ago infuriated the Kremlin and prompted separatists to launch a revolt across the Russian-speaking industrial east.
      
Kyivfor its part blamed the bus attack on "Russian terrorists" while monitors from the Organization for Security and Co-operation in Europe who raced to the site said all they could say for certain was that "the weapon used was most likely either a mortar or an artillery piece."       

Stunned residents in the eastern city gathered around the shredded remains of the bus and inspected with horror several bloodied bodies that remained sprawled in their seats hours after the early morning attack.
      
Kyivsuffered its biggest psychological blow on the bloody day when a small unit of Ukrainian paratroopers was forced to abandon its 242-day defence of Donetsk's once-gleaming but now ruined international airport.
      
A clam settled early on Friday over the shattered residential districts near the site after six days of some of the most intense rocket and mortar fire exchanges of the entire conflict.
      
The hub -- long stripped of its strategic importance by heavy shelling --...