Lawmakers and witnesses took to Twitter Wednesday to reassure their constituents, relatives and friends that they were safe amid a series of shootings around Canada's Parliament building. Reports indicated that a Canadian soldier had been killed, but details were still emerging as authorities rushed to secure government buildings in Ottawa.

It's unclear whether multiple gunmen were involved or whether the attacks were an act of terrorism, according to CNN. At least one shooter was dead, MP Bob Zimmer tweeted. There were also shootings at the nearby National War Memorial and Parliament Hill. Civic Hospital in Ottawa, the country's capital, received three patients, two of whom were in stable condition, according to ABC News.

The attack at Parliament began around 10 a.m. as Prime Minister Stephen Harper and other lawmakers prepared for caucus. Police moved to lock down large parts of Ottawa as they hunted down the potential shooters, according to reports. "The prime minister is safe and not on Parliament Hill and being briefed by security officials," his spokesman Jason MacDonald said.

U.S. President Barack Obama was briefed on the shootings, White House officials said. The violence came just days after Canada raised its terror alert Friday.