NEW YORK (CNN/Money) - The number of Americans filing for unemployment insurance jumped by 30,000 last week to the highest level since February, the government reported Thursday, with the figure well above economists' expectations.

Initial claims for unemployment insurance rose to 360,000 in the week ended April 10 from a revised 330,000 the previous week, the . Labor Department reported. The figure was above economists' estimates of 335,000 first-time claims, according to Brieifing.com.

The increase in initial claims was the largest weekly rise since December 2002.

Following the report, Treasury prices moved slightly higher, pushing the 10-year yield down to 4.36 percent. Stock futures held their ground and pointed to a higher opening for the stock markets.

Before Thursday's jobless report, the labor market has shown solid signs of improvement since the Labor Department issued its March payroll report, which showed companies added 308,000 jobs last month, well above expectations.

The March figures were followed by last week's report that showed initial claims at the lowest level in more than three years.

A Labor Department analyst cautioned, however, that the first full week of April was "pretty unpredictable" and difficult to adjust for seasonal variations. Still, he said there were no special factors to explain the jump in claims.

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The four-week average of initial claims, which irons out weekly fluctuations, rose by 6,750 to 344,250.

In the claims report, the department said the overall number of people on the benefit rolls who had already received an initial week of aid dropped 22,000 last week to 2.98 million, the lowest level since July 2001.  

--from staff and wire reports