* 12th weekly rise in U.S. drilling activity caps rises
* U.S. oil output could rise by 215,000 bpd in 2017- Goldman Sachs
By Henning Gloystein
SINGAPORE, April 10 (Reuters) - Oil prices were firm on Monday, supported by strong demand and political uncertainty in Syria, although another rise in U.S. drilling activity kept a lid on gains.
Brent crude futures, the international benchmark for oil, were at $55.39 per barrel at 0109 GMT, up 15 cents, or 0.3 percent, from their last close.
U.S. West Texas Intermediate (WTI) crude futures were up 24 cents, or 0.5 percent, at $52.48 a barrel.
Traders said prices were being supported by strong demand, and also political uncertainty following the U.S. missile air strikes on Syria late last week.
ANZ bank said on Monday that strong oil demand and "an unsettled global backdrop (is) leaving the market very finely balanced."
However, another increase in U.S. oil drilling, which has run up for 12 straight weeks to 672 rigs - the highest level since August 2015, kept markets from breaking last week's one-month highs of over $56 per barrel.
U.S. bank Goldman Sachs said following the rig data release that year-on-year U.S. oil production "would rise by 215,000 barrels per day in 2017" once a backlog of production waiting to be brought back online was taken into account.
Reporting by Henning Gloystein; Editing by Richard Pullin