Ukraine's acting president says its military is "on full combat alert" against a possible invasion by Russian troops massed on the border.
ພາບຫຼ້າສຸດ ຈາກ ຢູເຄຣນ
![An elderly couple dances as local citizens gather to observe May Day in Slovyansk, May 1, 2014.](https://gdb.voanews.com/89bfa6a5-f6b5-452d-bf27-b1bbe3573a06_w1024_q10_s.jpg)
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An elderly couple dances as local citizens gather to observe May Day in Slovyansk, May 1, 2014.
![Participants hold a Soviet flag near a statue of Soviet leader Vladimir Lenin during an International Worker's Day, or Labor Day, parade in the town of Slovyansk, May 1, 2014.](https://gdb.voanews.com/5d9318cc-7b2c-435f-bfad-d2c1a8966c34_w1024_q10_s.jpg)
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Participants hold a Soviet flag near a statue of Soviet leader Vladimir Lenin during an International Worker's Day, or Labor Day, parade in the town of Slovyansk, May 1, 2014.
![Participants shout slogans and wave Russian flags during an International Worker's Day parade in Donetsk, May 1, 2014.](https://gdb.voanews.com/9e35c0b4-8730-4221-abec-235ed0e00d37_w1024_q10_s.jpg)
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Participants shout slogans and wave Russian flags during an International Worker's Day parade in Donetsk, May 1, 2014.
![Local citizens march to observe May Day in the central square in Slovyansk, May 1, 2014.](https://gdb.voanews.com/5428430a-ee05-4e1a-a609-5653c160b5fe_w1024_q10_s.jpg)
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Local citizens march to observe May Day in the central square in Slovyansk, May 1, 2014.