WASHINGTON, April 22 (Xinhuanet) -- The number of US troops in Iraq has dropped below 140,000 this week from more than 150,000 before the Jan. 30 elections in the Arab country, a senior US defense official said on Friday.

    The number went down along with the completion of the latest American troop rotation in and out of the country, the official said at a Pentagon background briefing.

    General George W. Casey, the top commander in Iraq, has said that if all went well, the Pentagon should be able to take some fairly substantial reductions in the size of American forces earlynext year. Other senior military officials have said American force levels in Iraq could drop to around 105,000.

    Meanwhile, the number of "trained and equipped" Iraqi security forces now stood at more than 155,000, with 1,500 to 3,000 more soldiers and police joining the forces weekly, the official said.

    However, there was an increase in the number of attacks in Iraq,but the general trend was decreasing since the January elections, according to the official.

    In addition, there was also an increase in tensions among ethnic groups in various areas in Iraq, which was "a direct outgrowth" of the Abu Musab al-Zarqawi strategy, the official said."This is something the Iraqi government and the Iraqi security forces are going to have to deal with in the weeks and months ahead," he said. Enditem