By Cassie Werber

LONDON--Crude futures were higher Wednesday, pushed up by the geopolitical risk associated with further military developments in Ukraine.

Brent for June delivery was up 67 cents at $110.04 a barrel on ICE Futures Europe, on the first day of that month's contract. U.S. crude-oil futures was up 91 cents at $104.66 a barrel on the New York Mercantile Exchange.

While prices are higher, however, the gains remain modest.

"Investors it seems cannot believe that the situation will be allowed to blow up into a full blown war," David Hufton of brokerage PVM wrote in a note to clients.

"The next test will be tomorrow's meeting in Geneva of U.S., European Union, Russian and Ukrainian foreign ministers," he added.

JBC Energy also noted that there were other pressures at play.

"There are a number of factors that might be behind the recent strengthening of crude prices, including the Ukraine situation and other geopolitical risks, spiking gasoline prices, and U.S.-specific developments strengthening WTI," or West Texas Intermediate, the U.S. benchmark, they said.

The ICE's gasoil contract for May delivery was up $7.75 at $925.00 a metric ton, while Nymex gasoline for May delivery was down 6 points at $3.0415 a gallon.

Write to Cassie Werber at cassie.werber@wsj.com