NAIROBI, Kenya -- The Kenyan government will close Dadaab refugee camp, which has hundreds of thousands of Somali refugees and is often referred to as the world's largest camp, the East African country's interior security minister said Wednesday.

The decision has been condemned by domestic and international rights groups and organizations dealing with refugees.

Dadaab camp, with an estimated 328,000 refugees mostly from Somalia, compromises Kenya's security because it harbours some of Somalia's al-Shabab Islamic extremists and is a conduit for smuggling weapons, Joseph Nkaissery said.

He said al-Shabab planned three large-scale attacks from Dadaab.

Last week the Kenyan government announced it intends to close Dadaab as well as Kakuma, a refugee camp housing 190,000 people, mostly South Sudanese fleeing civil war. At the same time the interior ministry said it had disbanded the department of refugee affairs, which oversees the registration and welfare of refugees. But on Wednesday Nkaissery said Kakuma will not be closed because it does not present a security risk.

The U.N. has urged Kenya to reconsider its decision to close Dadaab camp. Spokesman Stephane Dujarric said Tuesday that the U.N. is calling on Kenya's government to avoid any action that is at odds with its international obligations.

Eleven non-governmental organizations operating in Kenya issued a statement Tuesday urging the government to reconsider the intended closure of the refugee camp.

Those signing the statement include the International Rescue Committee, World Vision, the Danish Refugee Council, Jesuit Refugee Service, Action Africa, Help International, the Lutheran World Federation, OXFAM, the Refugee Consortium of Kenya, Save the Children, the Norwegian Refugee Council and Heshima Kenya.

U.S. Secretary of State John Kerry in a statement late Wednesday said he was concerned by the decision to close the camps. He urged Kenya to continue its "leadership role in protecting and sheltering victims of violence and trauma, consistent with its international obligations."

The group urged other countries to expand their resettlement quotas for refugees coming from the Horn of Africa in order to help Kenya and share the burden of hosting refugees.

Associated Press writer Bradley Klapper in Washington contributed to this report.