Lebanon has begun limiting the flow of Syrians entering the country as it struggles to cope with a flood of asylum seekers fleeing the civil war next door.

The unprecedented restrictions that went into effect Monday establish new categories of entry visas for Syrians and sharply limit the period of time they may stay in Lebanon.

Lebanese officials say the new restrictions are necessary because their tiny country simply can't absorb more refugees. They estimate there are about 1.5 million Syrians in Lebanon, about one-quarter of the total population.

But the new restrictions, published on Lebanon's general security website, seemingly make no provisions for asylum seekers.

A security official, who spoke on condition of anonymity because he wasn't authorized to speak to press, said urgent humanitarian cases could still enter.