BEIJING (AFP) - Visiting US first lady Michelle Obama held a meeting on Sunday at the US embassy with Chinese educators and families, after her arrival there sparked a minor security alert.

Two people just outside the embassy began shouting as her motorcade pulled in, while police and men in grey sweatshirts and pants ran to subdue them.

It was unclear what they were shouting about.

Mrs Obama is making a week-long trip to China focused on education and "soft" issues.

US officials have stressed that the visit by Mrs Obama - who is accompanied by her daughters and mother - is not meant to touch on politics.

Since arriving in the capital on Thursday night, she has played table tennis with students and toured the Forbidden City with her counterpart Peng Liyuan.

But she briefly trod political ground in a speech on Saturday morning at Peking University's Stanford Centre, calling for greater freedoms while refraining from calling out China by name.

"As my husband has said, we respect the uniqueness of other cultures and societies," Mrs Obama told a crowd of about 200 students, most of whom were from the United States.

"But when it comes to expressing yourself freely, and worshipping as you choose, and having open access to information - we believe those are universal rights that are the birthright of every person on this planet," she said.

"We believe that all people deserve the opportunity to fulfil their highest potential as I was able to do in the United States."

Yet the majority of Mrs Obama's speech was devoted to encouraging American students to study abroad in China.

She touted the "100,000 Strong" initiative announced by President Obama during his 2009 visit to Beijing. The programme aims to raise the number and the socioeconomic diversity of Americans studying in China.

After her speech, Mrs Obama held a virtual roundtable with a group of American students, then took a tour with her family of the Summer Palace, a former imperial getaway not far from Peking University.

In opening remarks at the education roundtable on Sunday morning, she stressed that "education is an important focus for me".

"It's personal, because I wouldn't be where I am today without my parents investing and pushing me to get a good education," she said.

Mrs Obama also toured the Great Wall outside Beijing on Sunday.

She will also visit the northern city of Xian, site of the famous ancient Terracotta Warriors, and Chengdu in the southwest, home to the country's iconic pandas.