NEW YORK (CNN/Money) - The number of Americans filing for unemployment assistance rose by 12,000 last week, the government reported, coming in above economists' estimates for the second consecutive week.

Initial claims for unemployment insurance rose to 345,000 in the week ended May 15 from a revised 333,000 the previous week. Economists had expected initial claims of 326,000, according to Briefing.com.

Following the report, equity futures pointed to a flat to lower opening and Treasurys gained in price, with the 10-year yield falling to 4.75 percent.

The four-week moving average, which smoothes out weekly fluctuations in the report, fell to 333,500 from a revised 336,250 the previous week. The four-week moving average hit the lowest level since the week ended Nov. 18, 2000.

Continued claims, counting the number of people drawing benefits for more than a week, fell to 2.943 million in the week ended May 8 from a revised 2.966 million the previous week.