The main airport in Somalia's capital Mogadishu has been effectively shut down, following a threat by Islamist militants.

The militant group al-Shabab had warned it would attack any plane landing or taking off at the airport after midnight Tuesday.

Aviation officials say there are hundreds of soldiers guarding the airport Wednesday but that commercial airlines have ceased using the facility.

Somalia's civil aviation authority has told the airlines that if they do not maintain their normal schedules, they will lose their licenses.

Al-Shabab issued the airport threat on Saturday. The group says the airport generates money for the Somali government's Ethiopian backers, and is being used by American and Israeli spies.

The Somali government has dismissed the claim and says the airport will operate as normal.

On Monday, a human rights group said fighting in Somalia has killed nearly 9,500 Somalis since the start of the Islamist insurgency early last year. The Elman Human Rights Organization says that number includes 838 civilians killed since June.

The insurgents are seeking to drive out Ethiopian troops and topple the western-backed interim government.

Some information for this report was provided by Reuters.