AUSTIN, Texas (Reuters) - A 27-year-old Austin man was arrested on Friday and charged with placing an unexploded bomb containing some 2,000 nails outside an abortion clinic in the state’s capital.

The explosive device also included a propane tank and a mechanism “akin to a rocket,” Austin Police Commander David Carter said.

The device was discovered on Wednesday in the parking lot of the Austin Women’s Health Center, police said.

The Texas Joint Terrorism Task Force -- made up of federal, state and local law enforcement authorities -- arrested Paul Ross Evans, who authorities said was on parole for an unspecified crime.

Evans was charged with violating federal laws banning the manufacture of explosives and interfering with access to an abortion clinic. He appeared before a federal magistrate, and was being held without bail.

No further arrests were anticipated in the case. “The threat is over,” Carter said.

A robot was used to disarm the bomb after the unmarked clinic building and an apartment complex were evacuated, police said on Thursday.

This was the first bombing attempt this year at an abortion clinic, according to the National Abortion Federation, which tracks violence against abortion providers.

Four incidents of attempted bombing or arson were reported in 2006, the NAF said. More than 40 abortion clinic bombings have occurred since 1977, with the last reported in 2001.