Fri Dec 16, 2005 3:45 PM GMT

About 200 mothers wearing black gathered in an upmarket area of Lagos to deliver a letter of protest to the government when riot police surrounded them, witnesses said.

"We told them we were concerned mothers of Nigeria and we insisted on walking to government house, but they blocked the road and threw tear gas in front of us and behind us. Everyone scattered," said Bola Belgore, who was one of 17 women subsequently arrested.

She said the group had held the rally in solidarity with the mothers of the victims and had written to the police to request protection.

"We didn't think there could be any objection by anyone," Belgore said.

Lagos police spokesman Olabode Ojajuni denied that tear gas was used on the women.

"That is not true. The Commissioner of Police is handling the matter. We have met with the women," he said, without providing further details.

The December 10 crash of a 32-year-old DC-9 aircraft operated by Sosoliso Airlines was Nigeria's second major air tragedy in as many months.

The plane crashed at the Port Harcourt airport and burst into flames during a storm. An investigation is under way to determine the cause of the crash.

President Olusegun Obasanjo grounded Sosoliso and another privately owned airline on Tuesday and ordered an emergency audit of all aircraft in the oil exporting country, accusing the industry of corruption.

Belgore said the rescue effort after Saturday's crash was also flawed, and exposed the dire state of emergency services in Africa's most populous country.