Chad's leader has called for the urgent creation of a regional force to tackle Nigerian Boko Haram militants.The Islamist group operates in northern Nigeria, but President Idriss Deby said it was posing a threat to its neighbours around Lake Chad.
"Our basin is exposed to insecurity because of the permanent threat posed by Boko Haram," he said.
Nigeria has been struggling to contain attacks by the militants who want to impose Islamic law in the country.
On Monday, a suicide attack on a police station in Taraba state, which borders Cameroon, killed at least 11 people. No-one has claimed responsibility for the bombing, but Boko Haram militants have carried out many similar attacks.
They have targeted government institutions, churches and bars as well as mosques belonging to rival Muslim groups across northern Nigeria over the last 20 months.
Last year, the group also attacked the UN headquarters in Nigeria's capital, Abuja.
'Hideout' raided "I am demanding the creation of a joint deterrence force. We have to make this decision here today," President Deby told a meeting of the Lake Chad Basin Commission, which includes Chad, Cameroon, Niger, Nigeria and the Central African Republic.
"If we don't eradicate them, we won't be capable of saving our Lake Chad," he said.Some experts have warned that the group is building links with al-Qaeda in the Islamic Maghreb which has mainly been active in the Sahara - across Niger, Mali and Algeria.
In Nigeria on Tuesday morning, troops raided a suspected hideout of Boko Haram in the city of Kano.
The BBC's Yusuf Ibrahim Yakasai in Kano says a heavy gun battle started at about 04:00 GMT and continued for two hours, but security officials did not confirm whether the hideout belonged to Boko Haram.
Lieutenant Iweha Ikedichi told Reuters news agency that explosives and weapons were discovered during the raid in the Sabuwar Gandu area of the city.
An 18-year-old woman arrested in the raid told AFP news agency that her husband was a Boko Haram member and had escaped during the fighting.
The group has killed more than 1,000 people since it first came to prominence in 2009 when hundreds of its followers were killed when they attacked police stations in Maiduguri.
Its founder, Mohammed Yusuf, was arrested but died in police custody.
In 2010 the group, whose name means "Western education is forbidden", started to stage drive-by shootings on government targets in revenge for his killing.
Their attacks have killed hundreds of civilians, both Muslim and Christian.