The price of oil edged down Monday but stayed above $104 per barrel as investors watched simmering tensions in Ukraine.

U.S. crude for May delivery was down 12 cents at $104.18 in electronic trading on the New York Mercantile Exchange after trading resumed following a three-day holiday weekend. The contract rose 44 cents to $104.30 in the previous session.

Markets are on edge at the possibility of European or U.S. sanctions that might disrupt Russian supplies. Tensions were fueled by an Easter morning shooting at a checkpoint manned by pro-Russian insurgents.

Upward pressure on prices was offset last week by a U.S. Energy Department report that showed an increase of 10 million barrels of crude oil supplies, the largest in 13 years.

Brent crude, an international benchmark for oil, was down 38 cents at $109.15 on the ICE Futures exchange in London.