Twelve women US senators accused Myanmar's regime on Wednesday of using rape as a "weapon of war" and urged Secretary of State Hillary Clinton to pressure the government to halt the practice.

"Given the Burmese regime's unabated use of rape as a weapon of war, we urge you to call on the regime to end this practice and pursue our shared goal of establishing an international commission of inquiry into war crimes and crimes against humanity," the group wrote in a letter to Clinton.

"We must not allow this regime to continue to commit such dire crimes while the people of Burma continue to suffer," said the lawmakers, including Senate Intelligence Committee Chairwoman Dianne Feinstein.

Democratic Senators Barbara Boxer, Kay Hagan, Amy Klobuchar, Mary Landrieu, Barbara Mikulski, Patty Murray and Jeanne Shaheen, and Republican Senators Key Bailey Hutchison, Susan Collins, Lisa Murkowski, and Kelly Ayotte signed the letter.