NEW YORK (CNN/Money) - The fear of terrorism, never far from Americans' minds the past two years, appeared to be creeping back into U.S. stock trading early Monday after two car bombings in Turkey.

At 7:45 a.m. ET, futures pointed to a broadly lower open for the major indexes, after Tokyo's Nikkei index plummeted 3.7 percent overnight.

The terrorism concern was raised when car bombs exploded Saturday outside two synagogues in Istanbul. Turkish officials said at least 23 people were killed in the attacks. An Arab-language newspaper published in London said al Qaeda claimed responsibility for the attacks and is planning similar attacks in the United States, Japan and other allied nations.

The report helped send the Nikkei reeling, with the Japanese index finishing below 10,000 for the first time since August. Other Asian-Pacific markets also declined Monday, and European stocks began their day in retreat. (Check the latest on world markets)

Iraq also could weigh on U.S. markets after the crash of two Black Hawk helicopters killed 17 soldiers. U.S. forces have launched a new offensive on suspected insurgents near Saddam Hussein's home city of Tikrit. American officials also are trying to confirm if an audio tape aired by an Arabic language TV network actually contains the voice of Saddam urging continued resistance against U.S.-led forces that toppled him earlier this year.

Another merger in the financial services sector also will greet investors Monday. St. Paul Cos. (SPC: Research, Estimates) and Travelers Property Casualty Corp. (TAP.A: Research, Estimates) announced a merger agreement that the companies said would create the nation's second-largest commercial insurer.

With Travelers having just more than 1 billion A and B shares outstanding, the deal would be worth just over $16 billion based on Friday's closing prices. Travelers shareholders will have about 435 million shares in the new company, while St. Paul has 228 million shares outstanding.

Travelers' spokesman Keith Anderson said the deal is a merger of equals that does not have a premium, and that the exchange rate was calculated on a five-day average of the two company's stock prices.

Quarterly results from key retailers Lowe's and Toys 'R' Us will greet investors at the start of the trading week Monday.

No. 2 home improvement retailer Lowe's reported a 33 percent rise in its third-quarter profit, led by its expansion into metro areas. The company's results topped Wall Street's estimates and it guided higher for 2003.

Lowe's (LOW: Research, Estimates) shares inched higher in before-hours trading Monday.

Toys 'R' Us (TOY: Research, Estimates), the No. 1 specialty toy retailer, is forecast to post a loss of 9 cents a share, narrower than the 13 cents a share reported a year earlier. The company also will be watched for hints at what kind of holiday season it expects.

The firm's shares fell 26 cents to $12.74 Friday.

Before the markets open, the government will issue its report on business inventories for September. They're expected to come in unchanged after a 0.4 percent drop in August.

The Dow Jones industrial average finished on the negative side last week after dropping 0.7 percent Friday. The Nasdaq composite index was also lower; it fell 2 percent to conclude the week.

Treasury prices rose in early trading, sending the 10-year note yield down to 4.21 percent from 4.22 percent late Friday. The dollar gained against the yen, but was lower versus the euro.

Brent oil futures pulled back 35 cents to $29.21 a barrel in London. The concerns about terrorism helped send gold close to $398 an ounce.