Kenya sent extra troops to its border with Somalia on Wednesday to keep Islamic militants from entering the country after Ethiopian helicopters attacked a Kenyan border post by mistake while pursuing suspected fighters.

Meanwhile, Ugandan President Yoweri Museveni flew to the Ethiopian capital, Addis Ababa, to meet with Prime Minister Meles Zenawi to discuss the framework of a regional peacekeeping mission to Somalia, said Okello Oryem, the Ugandan minister of state of foreign affairs.

European backers of the Somali government were also meeting in Belgium to discuss how the European Union can support a possible peacekeeping mission for Somalia.

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Somalia's government forces, backed by Ethiopian troops, have been pursuing the remnants of the Islamic militia that until two weeks ago controlled most of southern Somalia and the capital, Mogadishu.

Four Ethiopian helicopters apparently mistook a Kenyan border post at Harehare for the Somali town of Dhobley on Tuesday and fired rockets at several small buildings, a security officer said on condition of anonymity because he was not authorized to speak to the media. There were no reports of casualties, but Kenyan tanks were sent to the area early Wednesday, the officer added.

Residents in Dhobley said they witnessed Ethiopian military aircraft bombing the area.

"Four military helicopters flew over our town several times and bombarded somewhere on the Kenyan side of the border," resident Mohamud Ilmi Osman said.

In the Kenyan port of Mombasa, Somalia's President Abdullahi Yusuf met with his Kenyan counterpart, Mwai Kibaki. Kibaki said Kenya would not be used as a refuge for people seeking to destabilize governments in the region — clearly referring to foreign fighters for the Somali Council of Islamic Courts who may be sought for terrorism and other crimes.

Kenya has deployed troops, armored vehicles and trucks with light weapons along the 400-mile border with Somalia. A U.S. counterterrorism task force has trained new coast guards and recently gave Kenya three patrol boats.

The U.N.'s humanitarian agency said about 4,000 Somali refugees were reported to be in the Dhobley area, unable to cross into Kenya. The agency gave no further details, but noted fears of newly laid land mines in southern Somalia following the latest fighting.

In nearby Liboi, UNHCR said it was trying to check reports Kenya had held 350-400 Somalis at the border since Dec. 27. "We can't confirm it because we have been denied access to the reception center by Kenyan security personnel," spokeswoman Millicent Mutuli told The Associated Press.

Kenyan government spokesman Alfred Mutua denied that security personnel had blocked U.N. refugee agency staff from getting to Liboi, but said border officials had instituted "rigorous security vetting" to ensure no fighters slipped in among the refugees. Only those that cleared the security check would be handed over to U.N. refugee officials, he said.

Somalia's government and its Ethiopian allies have long accused Islamic militias of harboring Al Qaeda, and foreign Islamic radicals — including Pakistanis, Arabs and Chechens — are believed to have come to Somalia to fight on behalf of the Islamic movement in recent months.

Three suspects wanted by the United States in the 1998 bombings of U.S. embassies in East Africa are believed to be leaders of the Somali Islamic movement.

Islamic movement leaders deny having any links to Al Qaeda.

There were signs that the Islamic movement may not be completely defeated. In the southern town of Jilib, a lone gunman on Tuesday killed three Ethiopians, including a commanding officer, witnesses said.

"A gunman shouting 'Allahu Akbar' attacked Ethiopian soldiers in Jilib town and killed three soldiers," businessman Muhuyadin Sheik Ibrahim said. "He attacked the soldiers three different times — morning, afternoon and evening. He escaped the first two attacks by foot but was killed in the last one."

Ibrahim said the attacker was one of 11 Islamic fighters who had stayed behind to launch such attacks, but that the other 10 had surrendered and returned to Mogadishu.

Islamic courts officials could not immediately be reached to confirm the report. Ethiopian officials declined to comment.