In late April, 65 Russian men in groups of five to 10 crossed the border with Ukraine on foot, telling border guards they were going to visit relatives.

It wasn't a fond babushka who picked them up at the border, however, but rather pro-Russian rebels from the self-declared Donetsk People's Republic in eastern Ukraine. They bussed the Russian fighters to the regional capital, where they took up arms and last week engaged in the fiercest combat yet against forces loyal to Kiev.

• The first Russian motherboard based on ARM-processor Baikal-M