Stock futures declined on Thursday as more details came to light in the investigation over the Trump campaign's ties to Russia. 

S&P 500 futures were down 0.22%, Dow Jones Industrial Average futures fell 0.3%, and Nasdaq futures slid 0.2%.

A report from Reuters said former National Security Adviser Michael Flynn and others in Donald Trump's presidential campaign had extensive contacts with Russian officials. According to Reuters sources, Flynn and others on Trump's team made contact with contacts associated with the Kremlin at least 18 times over the final seven months of the election.  

The revelation follows news Wednesday that the U.S. Department of Justice named former FBI Director Robert S. Mueller to head a probe into allegations that Russia interfered in last year's presidential elections and any ties between the Trump campaign and Moscow.

The latest report follows on from a turbulent week for Trump and his team. On late Tuesday, a New York Times report found that Trump asked former FBI Director James Comey to shut down the federal investigation into since-ousted National Security Adviser Michael Flynn. Flynn was forced to resign on Feb. 13 amid questions over his contact with the Russian ambassador and discussions of U.S. sanctions.

Comey wrote a memo detailing his conversation with the president shortly after it took place, according to the Times, which cited two people who read the document. It's part of a paper trail Comey created documenting what he believed to be improper efforts to influence the investigation. The president fired Comey, who was heading an investigation into the Trump campaign's alleged ties with Russia, early last week.

On Monday, news broke that Trump had divulged highly classified intelligence to Russia during a meeting last week, according to a report from The Washington Post. Trump reportedly shared top-secret information on the fight against ISIS with Russian Foreign Minister Sergey Lavrov and Russian Ambassador Sergey Kislyak in a meeting in which U.S. media was barred. The meeting had also raised eyebrows because it occurred just a day after Trump fired Comey.

These messy political developments in Washington spilled into financial markets on Wednesday in the most punishing day for stocks of 2017. The Dow fell 372 points, while the S&P 500 suffered its worst day since Sept. 9

Jobless claims in the U.S. fell in the past week, another sign of a healthy labor market. The number of new claims for unemployment benefit fell by 4,000 to 232,000. The less volatile, four-week average declined by 2,750 to 240,750. Continuing claims fell by 22,000 to 1.9 million, settling in at the lowest level since late 1988. 

Business conditions in the Philadelphia region improved at a faster pace in May, according to the latest Philadelphia Fed index. The measure increased to 38.8 in May from 22 in April, better than an expected reading of 18.5. 

Cisco ( CSCO - Get Report) tumbled nearly 8% in premarket trading after disappointing revenue guidance its current quarter. The tech company anticipates current-quarter sales to decline by 4% to 6%, indicating sales no higher than $12.13 billion. Analysts anticipated sales of $12.5 billion. Cisco also announced plans to lay off 1,100 jobs. The company had announced plans to reduce its workforce by 5,500 jobs back in August. 
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Walmart  (WMT - Get Report) rose 1% after topping net income estimates, though revenue came in slightly weaker than expected. Earnings rose to $1 a share from 98 cents in the same quarter a year earlier. Analysts anticipated earnings of 96 cents. Sales of $117.5 billion came in below estimates of $117.8 billion. U.S. same-store sales increased 1.4%. 

Ralph Lauren (RL - Get Report) climbed in premarket trading following a better-than-expected quarter. The fashion brand swung to a net loss of $2.48 a share from profit of 49 cents a share in the year-ago quarter. Adjusted earnings of 89 cents a share came in higher than consensus of 78 cents. Revenue of $1.57 billion came in ahead of estimates of $1.56 billion. 

Other earnings reports of note include L Brands (LB - Get Report) , Children's Place (PLCE - Get Report) , Buckle (BKS) , Bon-Ton Stores (BONT)  and Alibaba (BABA - Get Report) .